Arbitrage Calculator: Guaranteed Profit

An arbitrage calculator helps you split your stake across opposing outcomes at different sportsbooks to lock in profit regardless of which side wins. When the combined implied probability of all outcomes falls below 100 percent, you have found an arbitrage opportunity, also called a sure bet or arb.

Use our free arbitrage calculator below to find the optimal stake distribution for any 2-way or 3-way market. Enter your total bankroll and the odds from each sportsbook, and the calculator instantly shows how much to bet on each side.

The maths behind arbitrage betting is straightforward: if you can cover every possible outcome at prices that sum to less than 100 percent implied probability, you profit no matter what happens. The challenge lies in execution. Odds move quickly, sportsbooks can void bets, and account limits apply. This guide covers both the calculator workflow and the real-world steps needed to execute arbs successfully.

For a complete introduction to the strategy, read our arbitrage betting guide after using the calculator.

Arbitrage Betting Explained (and What the Calculator Does)

Arbitrage betting exploits pricing differences between sportsbooks. When two or more books disagree on the probability of an outcome, the combined odds can create a situation where betting on all sides guarantees a profit. This happens because each sportsbook sets its own lines based on its risk exposure, customer betting patterns, and internal models.

A sure bet, or arb, exists whenever the total implied probability across all outcomes drops below 100 percent. In a standard market without arbitrage, a sportsbook prices outcomes so the combined implied probability exceeds 100 percent. That difference is the vig, or juice, representing the book edge. When you find odds across different books where the combined implied probability dips under 100 percent, you can exploit that gap.

The arbitrage calculator performs several functions. First, it converts the odds you enter into implied probabilities. American odds require a specific formula: for negative odds, divide the absolute value by (absolute value plus 100), and for positive odds, divide 100 by (odds plus 100). Once the calculator has implied probabilities for each outcome, it sums them. If the total is under 100 percent, an arb exists.

Next, the calculator determines the optimal stake split. To guarantee equal profit regardless of outcome, you bet proportionally based on each outcome implied probability relative to the total. The calculator handles this automatically. You enter your total stake, and it tells you exactly how much to place on each side.

The calculator outputs include stake recommendations for each outcome, the guaranteed profit amount, the return on investment (ROI) percentage, and whether an arbitrage opportunity actually exists at the odds entered. If the combined implied probability exceeds 100 percent, the calculator will show there is no arb and display the book edge instead.

Understanding the difference between mathematical guarantees and execution reality is essential. The calculator shows what happens if both bets are placed successfully at the entered odds. In practice, odds can move between placing your first and second bet, sportsbooks can limit your stake or reject bets, and market rules can differ between books. A calculated arb is only locked in once both bets are confirmed at the expected odds.

The Arbitrage Formula (Implied Probability)

The core formula for finding arbitrage opportunities involves converting odds to implied probability and checking if the sum is below 100 percent.

For American odds, the conversion works as follows. When odds are negative, like -150, calculate: 150 divided by (150 plus 100), which equals 150 divided by 250, or 0.60 (60 percent implied probability). When odds are positive, like +200, calculate: 100 divided by (200 plus 100), which equals 100 divided by 300, or 0.333 (33.3 percent implied probability).

Once you have implied probabilities for all outcomes, add them together. If you find Side A at +110 on one book (implied probability: 47.6 percent) and Side B at +110 on another book (implied probability: 47.6 percent), the combined total is 95.2 percent. Since this is below 100 percent, an arb exists. The arb margin is 100 percent minus 95.2 percent, or 4.8 percent.

To calculate stakes, divide each outcome implied probability by the total combined probability, then multiply by your total stake. For the example above, each side would receive: (47.6 divided by 95.2) times your total stake, or about 50 percent each. The payout from either winning bet will exceed your total outlay, locking in profit.

For a deeper explanation of how odds relate to probability, see our vig and true odds calculator.

Arbitrage Calculator (Quick Start)

Getting started with our arbitrage calculator takes about 30 seconds. Here is what you need to know.

Step 1: Choose your market type. Select 2-way for spreads, totals, and moneylines where only two outcomes exist. Select 3-way for soccer, hockey, or any market with home win, draw, and away win options.

Step 2: Enter your total stake. This is the total amount you want to distribute across all outcomes. The calculator splits this optimally based on the odds entered.

Step 3: Enter the odds from each sportsbook. For 2-way markets, enter the odds for Side A and Side B. For 3-way markets, enter odds for home win, draw, and away win. Use American odds format (like +150 or -120).

Step 4: Review the results. The calculator instantly displays whether an arb exists, the recommended stake for each outcome, the guaranteed profit, and the ROI percentage.

A positive ROI means you have found an arbitrage opportunity. The calculator shows exactly how much to bet on each side to lock in that profit. If the ROI is negative or shows no arb, the odds entered do not create an arbitrage opportunity.

Our calculator supports American odds format, which is standard at US sportsbooks. If you have decimal odds, convert them first or use our odds converter.

Why use our arbitrage calculator? Speed matters in arb betting because odds change constantly. Our calculator is mobile-first and delivers instant results without page reloads. Enter odds, see your stakes, and place bets before the opportunity disappears.

The calculator also helps you understand why an arb exists by showing the combined implied probability and the margin. This information helps you evaluate whether the opportunity is worth pursuing based on the size of the edge and your ability to execute quickly.

Remember that the calculator shows mathematical outcomes. Execution risks remain. Gambling involves risk, and no tool eliminates that. Set limits, bet responsibly, and understand that even calculated arbs can fail if odds move or bets are rejected.

2-Way vs 3-Way Mode (Which Markets Use Which)

Choosing the correct market type is essential for accurate calculations. Using the wrong mode will produce incorrect stake recommendations.

Market Type	When to Use	Examples
2-Way	Markets with exactly two possible outcomes	Point spreads, totals (over/under), moneylines (no draw possible), NFL game lines, NBA spreads
3-Way	Markets with three possible outcomes including a draw	Soccer match result (1X2), NHL regulation-time moneyline, boxing decision markets

2-Way markets cover most US sports betting. When you bet an NFL spread or an NBA total, there are only two outcomes: Team A covers or Team B covers, over hits or under hits. Moneylines in football and basketball effectively function as 2-way because ties are extremely rare or result in a push.

3-Way markets appear primarily in soccer and hockey. Soccer match result markets include home win, draw, and away win. NHL regulation-time markets work similarly. In these cases, you need to bet all three outcomes to create a true arb.

A critical mistake is using 2-way mode for a 3-way market. If you only cover two of three outcomes in soccer, for example betting on home win and away win while ignoring the draw, you have not created an arb. If the match ends in a draw, you lose both bets.

Similarly, do not use 3-way mode for markets that only have two outcomes. Entering a third odds value when none exists will produce meaningless results.

Correlated outcomes also require caution. Some markets that appear separate are actually correlated, meaning the outcome of one affects the probability of another. For example, betting on a first-half total and a full-game total involves correlation because the first-half outcome directly influences the final total. True arbitrage requires independent, mutually exclusive outcomes.

How to Use This Arbitrage Calculator (Step-by-Step)

Successful arbitrage betting requires more than finding an arb on paper. You need a systematic workflow to execute before odds change. Follow these steps for each potential arb.

Step 1: Find candidate odds. Before using the calculator, identify potential arbs through line shopping across multiple sportsbooks. Look for markets where different books show significantly different prices on opposing sides. Spreads, totals, and moneylines on major sports offer the most opportunities because of high liquidity and frequent price updates.

Step 2: Verify market rules match. Confirm that both sportsbooks are pricing the same market with identical settlement rules. Common mismatches include overtime rules (does the bet include overtime or only regulation?), push rules (what happens if the spread lands exactly on the number?), and player prop specifics (does the player need to start, or just play?). A seemingly profitable arb can turn into a guaranteed loss if settlement rules differ.

Step 3: Enter odds into the calculator. Open our arbitrage calculator, select the appropriate market type, enter your total stake, and input the odds from each book. The calculator displays whether an arb exists and the optimal stakes.

Step 4: Check for execution feasibility. Before placing bets, verify that each sportsbook will accept the recommended stake. Check maximum bet limits, which vary by sport, market, and your account status. If your recommended stake exceeds what a book will accept, the arb may not be executable at full size.

Step 5: Place bets using two devices. Speed is critical. Have both sportsbooks open simultaneously on separate devices (phone and laptop, or two phones). Place the smaller stake bet first when possible, as it is less likely to move the line. Then immediately place the second bet. The goal is completing both bets before either price changes.

Step 6: Verify bet confirmations. Check that both bets are confirmed at the expected odds. Review the bet slip details on each sportsbook. If one bet was accepted at different odds than expected, recalculate to determine if the arb still exists.

Step 7: Record the arb. Log the bets, odds, stakes, and expected profit for tracking purposes. This helps with bankroll management and identifying patterns in where arbs appear.

Checkpoint	Action	If Failed
Market rules match	Compare settlement terms on both books	Abandon this arb
Stake limits allow full bet	Check max bet on both sides	Reduce stake or abandon
Odds still available	Refresh both books before betting	Recalculate or abandon
Both bets confirmed	Check bet slips on each sportsbook	See troubleshooting section

Stake rounding considerations: The calculator may recommend stakes like $47.62 on Side A and $52.38 on Side B. Most sportsbooks require whole dollar amounts or limit decimal places. When rounding, always recalculate to ensure the arb remains positive. Round down on both sides if necessary, then verify the ROI is still positive with the adjusted stakes.

Worked Walkthrough (Simple 2-Way Example)

Here is a complete example of identifying and executing a 2-way arbitrage opportunity.

Scenario: You are shopping NFL Week 12 spreads and notice the following prices for the same game:

• Sportsbook A: Chiefs -3 at +105
• Sportsbook B: Opponents +3 at +105

Both sides are priced at +105, which is unusual. Normally, one side would be around -110 to -115. This pricing discrepancy signals a potential arb.

Step 1: Calculate implied probabilities.

Chiefs -3 at +105: 100 / (105 + 100) = 100 / 205 = 48.78%

Opponents +3 at +105: 100 / (105 + 100) = 100 / 205 = 48.78%

Combined: 48.78% + 48.78% = 97.56%

Since 97.56% is less than 100%, an arb exists. The arb margin is 2.44%.

Step 2: Enter into calculator.

Open the arbitrage calculator, select 2-way mode, and enter:

• Total stake: $1,000
• Side A odds: +105
• Side B odds: +105

Step 3: Review results.

The calculator shows:

• Stake on Chiefs -3: $500.00
• Stake on Opponents +3: $500.00
• Guaranteed profit: $25.00
• ROI: 2.5%

Step 4: Execute bets.

Open Sportsbook A on your phone and Sportsbook B on your laptop. Navigate to the same game spread market on each. Place the $500 bet on Chiefs -3 at Sportsbook A first. Immediately place the $500 bet on Opponents +3 at Sportsbook B.

Step 5: Verify confirmation.

Check that both bet slips show the expected odds (+105 each) and stakes ($500 each). Your total outlay is $1,000.

Outcome analysis:

If Chiefs win by 4 or more points, the Chiefs -3 bet wins. Payout at +105 for $500 stake: $500 + $525 = $1,025. Total profit: $1,025 - $1,000 = $25.

If Opponents cover (Chiefs win by 2 or fewer, or lose), the Opponents +3 bet wins. Payout at +105 for $500 stake: $500 + $525 = $1,025. Total profit: $1,025 - $1,000 = $25.

If Chiefs win by exactly 3, both bets push, and your full $1,000 is returned.

Regardless of outcome, you profit $25 or break even. This is the essence of arbitrage betting.

Worked Examples by Sport and Market

Different sports and markets present distinct arbitrage characteristics. Understanding these helps you identify opportunities and avoid common pitfalls. The examples below walk through realistic scenarios including both successful arbs and near-misses to illustrate what separates profitable opportunities from standard betting situations.

Example 1: NFL Spread (2-Way)

Market: Cowboys vs. Eagles, point spread

NFL spreads are among the tightest markets in sports betting because of massive liquidity and sharp bettors constantly correcting inefficiencies. Arbs appear briefly, typically when injury news breaks or when one book is slow to update after line movement elsewhere.

Initial odds found through line shopping:

• Sportsbook A: Cowboys +3.5 at -105
• Sportsbook B: Eagles -3.5 at -105

Implied probability calculation:

• Cowboys +3.5: 105 / (105 + 100) = 51.22%
• Eagles -3.5: 105 / (105 + 100) = 51.22%
• Combined: 102.44%

This is NOT an arb. The combined implied probability exceeds 100%. This is the normal situation where the house has an edge. You would need to find better prices to create an arb.

Continued line shopping: After checking six more sportsbooks, you find:

• Sportsbook C: Cowboys +3.5 at +100
• Sportsbook D: Eagles -3.5 at +100

Recalculate:

• Cowboys +3.5 at +100: 100 / 200 = 50%
• Eagles -3.5 at +100: 100 / 200 = 50%
• Combined: 100%

Still no arb, just a break-even scenario. But you keep looking and find Sportsbook E has not yet adjusted to morning line movement.

The actual arb opportunity:

• Sportsbook C: Cowboys +3.5 at +100 (50% implied)
• Sportsbook E: Eagles -3.5 at +102 (49.50% implied)
• Combined: 99.50%

Now an arb exists with a 0.50% margin.

Calculator inputs:

• Total stake: $2,000
• Side A (Cowboys +3.5): +100
• Side B (Eagles -3.5): +102

Results:

• Stake on Cowboys +3.5: $1,005.03
• Stake on Eagles -3.5: $994.97
• Guaranteed profit: $10.00
• ROI: 0.50%

NFL-specific execution notes:

• Sunday morning before games is prime time for NFL arbs as books adjust to late injury reports at different speeds
• Key numbers (3, 7, 10) matter: a spread of exactly 3 has push risk that affects both sides identically, maintaining the arb
• Alt spreads (Cowboys +7.5, Eagles -7.5) are less liquid and may offer larger arb windows but with lower maximum stakes
• Monday and Thursday night games have tighter lines due to concentrated betting volume

Example 2: NBA Total (2-Way)

Market: Lakers vs. Celtics, total points 224.5

NBA totals are fertile ground for arbitrage opportunities. Injury news, rest decisions, and pace-of-play adjustments cause frequent line movement, and different sportsbooks react at different speeds. Totals also see less sharp action than spreads, creating more persistent inefficiencies.

Odds found:

• Sportsbook A: Over 224.5 at +102
• Sportsbook B: Under 224.5 at +102

Implied probability:

• Over: 100 / 202 = 49.50%
• Under: 100 / 202 = 49.50%
• Combined: 99.01%

An arb exists. Arb margin: 0.99%.

Calculator inputs:

• Total stake: $2,000
• Over odds: +102
• Under odds: +102

Results:

• Stake on Over: $1,000
• Stake on Under: $1,000
• Guaranteed profit: $20
• ROI: 1.00%

Outcome verification:

If the game ends 118-112 (230 total points), the Over wins. Payout: $1,000 stake + $1,020 profit = $2,020. Net after losing the Under stake: $2,020 - $2,000 = $20 profit.

If the game ends 108-110 (218 total points), the Under wins. Payout: $1,000 stake + $1,020 profit = $2,020. Net after losing the Over stake: $2,020 - $2,000 = $20 profit.

NBA totals execution notes:

• Totals move frequently based on injury news and betting volume, especially in the two hours before tip-off
• Place bets close to game time when lines are most stable, but not so close that odds are pulled
• Verify both books are using the same total (224.5 in this case, not 224 or 225)
• Check if either book has half-point rules that differ
• Back-to-back games and rest days significantly affect totals and create movement opportunities
• First and second half totals can also present arb opportunities with less scrutiny than full-game lines

Example 3: Soccer 1X2 (3-Way)

Market: Premier League, Manchester United vs. Chelsea, match result (90 minutes)

Soccer presents unique arbitrage opportunities because of the three-way market structure. The draw outcome adds complexity but also creates more pricing variance across books. European sportsbooks, US books, and betting exchanges often disagree significantly on draw probabilities, making soccer 1X2 a consistent source of arbs.

Odds found across three books:

• Sportsbook A: Manchester United win at +180
• Sportsbook B: Draw at +280
• Sportsbook C: Chelsea win at +175

Implied probability:

• Man Utd win: 100 / 280 = 35.71%
• Draw: 100 / 380 = 26.32%
• Chelsea win: 100 / 275 = 36.36%
• Combined: 98.39%

An arb exists. Arb margin: 1.61%.

Calculator inputs (3-way mode):

• Total stake: $1,000
• Home (Man Utd) odds: +180
• Draw odds: +280
• Away (Chelsea) odds: +175

Results:

• Stake on Man Utd: $358.21
• Stake on Draw: $263.17
• Stake on Chelsea: $378.62
• Guaranteed profit: $16.10
• ROI: 1.61%

Outcome verification:

If Manchester United wins at +180, payout on $358.21 stake = $358.21 + ($358.21 x 1.80) = $1,002.99. Total wagered was $1,000. Profit: $2.99. (Note: slight rounding differences from calculator output.)

If the match draws at +280, payout on $263.17 stake = $263.17 + ($263.17 x 2.80) = $1,000.05. Profit: approximately $0.05.

If Chelsea wins at +175, payout on $378.62 stake = $378.62 + ($378.62 x 1.75) = $1,041.20. Profit: $41.20 minus the $1,000 total stake = approximately $41.

The calculator optimizes stakes so each outcome returns approximately equal profit. Minor discrepancies arise from rounding to two decimal places.

Soccer-specific execution notes:

• 3-way arbs require coverage of all three outcomes. Missing the draw leaves you exposed to the most unpredictable result
• Soccer lines can change rapidly before kickoff, especially for Premier League and Champions League matches
• Different books may offer draw no bet or other variations that are NOT the same as 1X2
• Verify all three bets are for 90-minute result, not including extra time or penalty shootouts
• League-specific knowledge helps: lower leagues have less efficient markets and larger arb windows
• In-play soccer betting can create brief arb windows, but execution speed is even more critical
• Asian handicap markets are different from 1X2 and require separate calculation approaches

Example Library (Quick Reference)

Sport/Market	Mode	Where Arbs Appear	Watch For
NFL spreads	2-way	Line movements, alt spreads	Push rules, key numbers
NBA totals	2-way	Fast line moves, injury news	Half-point differences
MLB moneylines	2-way	Underdog pricing gaps	Listed pitcher rules
NHL regulation ML	3-way	Draw pricing variance	Regulation only vs. full game
Soccer 1X2	3-way	Draw odds discrepancies	90 min vs. full time
Props (2-outcome)	2-way	Books with different lines	Settlement rules vary widely

Markets where arbs commonly appear:

• Alternate spreads and totals: Less liquid markets have more pricing variance. Alt lines like Team -7.5 instead of -3.5 see less betting volume, so books adjust slower.
• Player props: Different books offer different lines on the same prop. One book might have Player Over 22.5 points at -110 while another has Under 23.5 at -110, creating overlap opportunities.
• Live betting: Rapid odds movement creates brief arbitrage windows. Books update at different speeds during games, especially after scoring plays or momentum shifts.
• Smaller markets: College sports, lower soccer leagues, and niche events have less efficient pricing. Books rely more on models than market feedback.
• Cross-book specialization: Some books price certain sports more aggressively. A book focused on NFL might have looser NBA lines compared to an NBA specialist.
• Promotional odds boosts: When one book offers a boosted price on an outcome, it can create temporary arbs against standard pricing elsewhere.
• Opening lines: Early lines before sharp money moves the market often have the most inefficiency. Sunday morning NFL openers and Tuesday NBA lines are prime hunting grounds.
• Correlated parlays and same-game props: While not traditional arbs, understanding correlation helps identify when books misprice related outcomes.

How to Find Arbitrage Opportunities (Without Getting Burned)

Finding arbs starts with systematic line shopping. You need to compare odds across multiple sportsbooks simultaneously to spot pricing discrepancies. The more books you monitor, the more opportunities you can find.

Building your sportsbook foundation:

Open accounts at multiple legal sportsbooks in your state. Each additional account increases your chance of finding arbs because you can access more unique odds. Fund accounts in advance so you can bet immediately when opportunities appear. Waiting to deposit wastes precious time as odds move.

Aim for at least 5-7 active sportsbook accounts to start. In states with robust sports betting markets, you may have access to 10-15 or more licensed operators. The marginal value of each additional account decreases, but even books you rarely use might occasionally offer the exact price you need to complete an arb.

Prioritize books that commonly appear on opposite sides of markets. Through experience, you will learn which books tend to be slow to adjust (creating stale line opportunities) and which books tend to shade lines differently based on their customer base.

Scanning for opportunities:

Develop a routine for checking prices. Focus on high-volume markets during peak betting times. NFL spreads on Sunday morning, NBA totals an hour before tip-off, and soccer 1X2 lines on match day all see heavy action and frequent price adjustments. Pricing gaps appear when one book is slow to adjust to new information or betting volume.

Structure your scanning by sport and market type:

• Morning routine (8-10 AM ET): Check overnight line movements on that day games. Early NFL lines on Sunday mornings often have inefficiencies before sharp money arrives.
• Pre-game windows: Focus on the 1-2 hours before tip-off when lines are most active but still stable enough to execute.
• News reaction periods: When injury reports drop or starting lineups are announced, some books adjust faster than others. This creates brief windows.
• Late-night markets: International soccer and overnight games may have less attention from sharp bettors, leaving more room for arb opportunities.

Avoid the trap of constantly refreshing odds all day. This leads to burnout and impulsive betting. Structured scanning sessions are more sustainable and often more profitable.

The critical checklist before betting:

Check	Question to Ask	Risk if Ignored
Same market	Are both bets on the same game and outcome type?	Betting wrong market voids arb
Same timeframe	Do both bets cover the same period (full game, 1H, etc.)?	Different periods are not opposing bets
Same settlement rules	What happens on pushes, overtime, voided games?	Rule differences cause one bet to win while other pushes
Same line number	Is it the same spread or total number?	Different numbers are not true opposites
Stake limits	Will both books accept your intended stake?	Partial fills leave you unbalanced
Account standing	Are you already limited at either book?	Bets may be rejected or reduced

Speed tactics for execution:

Speed separates successful arb bettors from those who constantly miss opportunities. Every second matters when odds can change at any moment.

• Pre-login: Stay logged into all sportsbook apps. Session timeouts waste critical seconds. Use password managers with biometric unlock for quick re-authentication.
• Pre-fund: Keep balances ready across all accounts. Waiting for deposits costs opportunities. Maintain minimum balances that cover your typical arb stake.
• Two-device setup: Use phone and laptop simultaneously. Place both bets within seconds. Some bettors use two phones to make both bets in the same physical motion.
• Shortlist books: Know which 3-4 books most often have opposite prices. Over time, you will identify book pairs that frequently create arb opportunities together.
• Set alerts: Some tools notify you of line movements or price discrepancies. Line movement alerts help you react faster than manual checking.
• Practice the motion: Before betting real money on time-sensitive arbs, practice the physical process of placing simultaneous bets. Know exactly where each button is on each app.
• Have bet slips ready: Pre-populate bet slips with the game and market before confirming the arb exists. This saves navigation time when you need to execute.

Understanding why arbs exist:

Arbs appear because sportsbooks operate independently and manage their own risk. If one book has heavy action on Team A, it may shade its line to attract bets on Team B. Meanwhile, another book with opposite action might shade the other direction. This creates temporary pricing gaps.

Arbs also appear due to:

• Stale lines: One book is slow to update after news breaks. Smaller books or those with less sophisticated pricing models often lag behind market leaders.
• Regional differences: Books in different markets have different customer bases. A book popular with NFL bettors may have less efficient NBA lines.
• Risk management: Books may offer better prices on outcomes they want more action on. A book heavily exposed on one side will shade toward the other.
• Promotions: Boosted odds can temporarily create arbitrage windows. When a book offers +200 on something normally priced at +150, the other side may now be arb-able.
• Model disagreements: Different books use different pricing models. Legitimate disagreement about true probability creates natural arb opportunities.
• Timing differences: Some books update immediately on news, others wait. Early-game live betting often shows the largest discrepancies as books catch up to in-game developments.

Bankroll, Accounts, and Operational Setup

Successful arbitrage betting requires proper infrastructure. Your bankroll, account distribution, and record-keeping systems all affect profitability. Treating arb betting like a business operation rather than casual gambling leads to better results and fewer costly mistakes.

Bankroll tiers for arb betting:

Tier	Starting Bankroll	Accounts Needed	Expected Monthly ROI
Starter	$1,000-$2,500	3-5 sportsbooks	1-3% (if executing well)
Intermediate	$5,000-$15,000	6-10 sportsbooks	2-5% (more volume possible)
Advanced	$25,000+	10+ sportsbooks	3-6% (with experience and discipline)

These ROI figures assume consistent execution without major errors. Real-world results vary based on your market, the number of available sportsbooks in your state, and how much time you dedicate to finding and executing arbs. Starting with a smaller bankroll is wise while you learn the execution mechanics.

Distributing capital across sportsbooks:

Do not keep all your money at one or two books. Arbs require betting opposite sides at different books, so your capital needs to be spread across accounts. A general approach is to keep roughly equal balances at each book you actively use, adjusting as needed based on where you find the most opportunities.

Start by identifying which books most often appear on opposite sides of your arbs. These become your primary accounts. Keep higher balances at these books. Secondary accounts with less frequent opportunities can hold smaller amounts.

Capital rebalancing strategy:

After settling a series of arbs, you will notice your balances become uneven. If you win at Book A and lose at Book B across multiple arbs, Book A balance grows while Book B shrinks. Eventually, Book B runs low and you cannot execute arbs that require it.

Regular rebalancing is essential. Options include:

• Withdraw and redeposit: Pull funds from books with excess balance and deposit into books that need replenishing. This is straightforward but may trigger account reviews if done frequently.
• Bet sizing adjustment: Temporarily reduce stake sizes at low-balance books while building them back up organically through wins.
• Accept temporary imbalance: Sometimes waiting for balances to naturally equalize through varied arb outcomes is simpler than frequent transfers.

Withdrawal timing and liquidity:

Sportsbook withdrawals take time, typically 1-5 business days depending on the method. This affects your available capital. If you tie up funds waiting for withdrawals, you cannot bet those dollars on new arbs.

Consider keeping some cash reserve outside sportsbooks to cover new opportunities while waiting for withdrawals. A reserve equal to 10-20% of your total arb bankroll provides flexibility for quick deposits when needed.

Be aware that frequent deposits and withdrawals may trigger sportsbook reviews or account restrictions. Some bettors minimize transfer frequency by rebalancing less often but in larger amounts.

Withdrawal methods matter. Bank transfers are typically free but slower. PayPal or Venmo may be faster but have limits. Understand each book withdrawal options and processing times.

Record-keeping basics:

Track every arb bet for two purposes: bankroll management and tax awareness. Log the date, sportsbooks used, markets bet, odds, stakes, and outcome. Calculate your actual profit after settlement.

Essential data to track for each arb:

• Date and time of execution
• Both sportsbooks used
• Market and event details
• Odds entered and odds confirmed
• Stakes placed on each side
• Expected profit vs. actual profit
• Any execution issues encountered

This tracking helps identify patterns: which books offer the best prices, which markets produce the most arbs, and whether your execution is capturing the calculated ROI. It also provides documentation for tax purposes, though you should consult a tax professional for specific guidance on your situation.

A simple spreadsheet works for most bettors. More advanced setups integrate with sportsbook APIs or use dedicated betting tracking software. The key is consistency: log every bet immediately, not from memory days later.

Account sustainability:

Sportsbooks monitor for arb betting behavior. Excessive winning, unusual bet patterns, or consistently betting both sides of markets may draw attention. This is discussed further in the legality section, but from a bankroll perspective, understand that accounts can be limited or closed. Diversifying across many books and maintaining recreational betting behavior alongside arbs can help extend account longevity.

Risks, Limits, and Why Guaranteed Profit Can Fail

The arbitrage calculator shows mathematically guaranteed profit. In practice, multiple factors can cause actual outcomes to differ. Understanding these risks helps you make informed decisions about whether and how to pursue arbs.

Odds movement between bets:

This is the most common reason arbs fail. Odds change constantly. If you place your first bet at +105 and the opposite side moves from +105 to -110 before you can bet, the arb no longer exists. You now have an unhedged position.

Mitigation: Execute as fast as possible using two devices. Place the smaller stake first (less likely to move the market). Accept that some arbs will disappear mid-execution.

Bet rejection or limit restrictions:

Sportsbooks can reject bets or limit your stake below what you requested. If you enter $500 as your stake but the book only accepts $100, your calculated arb is now unbalanced. The remaining $400 you intended to bet is not deployed, and your total stake distribution is wrong.

Mitigation: Check stake limits before betting large amounts. Start with smaller arb sizes to understand each book limits for your account.

Voided bets and settlement disputes:

Sportsbooks can void bets for various reasons: palpable errors (obviously wrong odds), cancelled games, or rule violations. If one side of your arb is voided while the other stands, you now have an unhedged single bet.

For example, if Sportsbook A voids your bet at +105 due to a palpable error, but Sportsbook B bet stands, you have lost your guaranteed profit and now face regular betting risk on just one side.

Mitigation: Be cautious of odds that seem too good to be true. Extremely favorable lines may be errors that books will void. Read sportsbook terms on void conditions.

Settlement rule differences:

Even when betting the same game, different sportsbooks may have different rules for pushes, overtime, or specific situations. If Sportsbook A includes overtime in their spread settlement but Sportsbook B only counts regulation time, you are not betting true opposites.

This can result in both bets losing or one bet winning while the other pushes, destroying your arb.

Mitigation: Read settlement rules carefully. When in doubt, contact customer support to confirm how each book settles the specific market.

Human error:

Mistakes happen under time pressure. Common errors include:

• Betting the wrong team or outcome
• Entering the wrong stake amount
• Betting a different line number than intended (team -3 instead of -3.5)
• Using wrong odds format (mistaking decimal for American)
• Betting the wrong game entirely

Mitigation: Slow down enough to verify before confirming. Double-check team names, line numbers, and stakes. Accept that perfect execution requires discipline.

Clear reality check:

Arbitrage betting is mathematically profitable in theory. In execution, the guaranteed profit only materializes when both bets are confirmed at expected odds with matching settlement rules. Any deviation from the calculated scenario introduces risk. The term guaranteed applies to the math, not to real-world outcomes.

Common Errors and Fixes (Troubleshooting Hub)

Problem	What Happened	How to Fix
ROI turned negative after rounding	Rounding stakes up pushed total above break-even	Recalculate with rounded-down stakes; verify positive ROI remains
One bet placed, odds moved on second	Price changed before completing both bets	Recalculate with new odds; proceed if still profitable or consider hedging
Max stake blocked	Sportsbook limited your bet below intended stake	Reduce other side proportionally or abandon arb
Market voided on one book	Book voided bet as palpable error or due to event cancellation	If game still active, consider hedging remaining exposure using the hedge calculator
Different settlement outcome	Books had different overtime or push rules	No fix retroactively; verify rules before betting in future
Account limited after arb	Sportsbook restricted your betting limits	Reduce frequency at that book; diversify across more accounts

Handling the one bet placed, other side moved scenario:

This is the most stressful situation in arb betting. You have placed $500 on Side A at +105, expecting to complete the arb with $500 on Side B at +105. But Side B is now at -105.

Option 1: Recalculate the arb. At -105, Side B implied probability is 51.22%. Combined with Side A at 47.62%, the total is 98.84%. An arb still exists, just smaller. Recalculate optimal stakes for the new odds.

Option 2: Bet the new odds anyway. The arb margin is smaller, but you might still lock in some profit. Run the numbers.

Option 3: Do not bet and accept the single-bet exposure. You now have a standard bet on Side A. This is risky but sometimes the right call if the new odds create a negative arb.

Option 4: Consider a hedge. If you want to limit downside, use our hedge calculator to find a stake that guarantees you break even or minimizes loss.

There is no perfect answer. Speed, discipline, and willingness to walk away from bad setups are your best tools.

Legality and Account Limit Reality in the US

Arbitrage betting is a legal strategy in the United States. You are not breaking any laws by placing bets at different sportsbooks to guarantee a profit. Sportsbooks offer odds publicly, and you are free to shop those odds and bet where you see value.

However, legal does not mean without consequences. Sportsbooks are private businesses that reserve the right to limit or close accounts for any reason. Their terms of service typically allow them to restrict users who they believe are not recreational bettors.

The legal landscape:

Sports betting is regulated at the state level. Each state where sports betting is legal has its own rules and licensed operators. The act of arbitrage betting itself is not prohibited by any state sports betting law. You are simply placing legal bets at licensed sportsbooks.

As of late 2024, over 35 states plus Washington D.C. have legalized some form of sports betting. The number of licensed operators varies significantly by state. States like New Jersey, Pennsylvania, and Colorado have 15+ active sportsbooks, creating more arbitrage opportunities. States with fewer operators naturally have fewer arb possibilities.

Tax obligations apply. Sportsbook winnings are taxable income. While this guide does not provide tax advice, be aware that profitable betting generates tax liability. The IRS considers gambling winnings as income, and sportsbooks issue W-2G forms for large wins. Keep detailed records of all betting activity. Consult a tax professional for guidance specific to your situation, especially regarding how to handle the unique accounting of arb betting where you have offsetting wins and losses across books.

For broader context on where sports betting is legal, the American Gaming Association maintains resources on state-by-state availability.

The account limit reality:

Sportsbooks make money when bettors lose. Arb bettors, by definition, do not lose on properly executed arbs. This makes arb bettors unprofitable for sportsbooks, which leads to account restrictions.

Common patterns that trigger sportsbook attention:

• Consistently betting maximum stakes
• Betting both sides of the same market across accounts (detected via shared data between books)
• Unusual winning percentage over time
• Betting primarily on sharp lines that move the market
• Rapid deposits and withdrawals
• Taking odds that are clearly mispriced (palpable errors)
• Betting only when lines diverge from market consensus
• Never taking promotions or bonus bets (which signal purely strategic betting)

When flagged, sportsbooks may:

• Lower your maximum bet limits (often dramatically, to as low as $5-$10)
• Delay bet approval requiring manual review
• Remove promotional offers and bonuses
• Close your account entirely
• Void pending bets in extreme cases (usually only for clear terms violations)

These restrictions can happen without warning or explanation. The sportsbook terms of service give them this discretion. You typically have no recourse beyond withdrawing your remaining balance.

Sustainable practices:

Some arb bettors try to extend account longevity by mixing recreational betting with arb betting, betting smaller amounts, and avoiding certain signals. There is no guaranteed way to avoid limits indefinitely. If you consistently take value from books, they will eventually notice.

Tactics that may help extend account life:

• Round bet amounts to normal-looking figures ($50, $100) rather than precise calculator outputs ($47.62)
• Place some recreational bets on popular markets without arb value
• Use promotional offers and bonus bets when available
• Avoid betting the same market at multiple books within minutes
• Do not always bet maximum stakes
• Spread activity across multiple sports rather than specializing

Accepting account limits as a cost of doing business helps manage expectations. Having multiple accounts across many sportsbooks increases your runway. When one account gets limited, you move volume to others.

Avoid any account practices that violate sportsbook terms, such as using someone else identity to open accounts or attempting to circumvent restrictions through VPNs or false information. Stick to legal, ethical practices. Violations can result in forfeited balances and potential legal consequences.

Alternative approaches:

If arbitrage betting draws too much sportsbook attention, consider exploring related strategies that offer value without the same level of scrutiny. Expected value betting identifies positive EV opportunities without requiring opposite bets. Line shopping ensures you get the best available price on every bet you make. These approaches compound value over time with potentially less book friction.

The hedging strategy described in our hedge calculator guide offers another path. Rather than seeking pure arbs, you can hedge existing positions to lock in profit or minimize loss on bets you have already made. This looks more like normal betting behavior to sportsbooks.

Frequently Asked Questions

How does an arbitrage calculator work?

An arbitrage calculator converts the odds you enter into implied probabilities, then checks if the combined total is below 100 percent. If it is, an arb exists. The calculator then determines the optimal stake to place on each outcome so that whichever side wins, your payout exceeds your total stake by the same amount. You enter your total bankroll and the odds from each sportsbook, and the calculator tells you exactly how much to bet on each side.

How do you calculate arbitrage betting?

To calculate an arb manually, first convert each set of odds to implied probability. For American odds, negative odds use the formula: absolute value divided by (absolute value plus 100). Positive odds use: 100 divided by (odds plus 100). Add the implied probabilities together. If the sum is below 100 percent, an arb exists. To find optimal stakes, divide each outcome probability by the total, then multiply by your desired total stake. Most bettors use a calculator because manual calculation under time pressure leads to errors.

Can arbitrage betting guarantee profit?

In theory, yes. If you successfully place both bets at the calculated odds, your profit is mathematically guaranteed regardless of outcome. In practice, several factors can prevent this guarantee: odds moving before you complete both bets, sportsbooks limiting or rejecting your stakes, one bet being voided, or settlement rules differing between books. The guarantee applies only when both bets are confirmed at expected odds with matching settlement terms.

Is arbitrage betting legal in the US?

Yes. Arbitrage betting is legal everywhere sports betting is legal in the United States. You are simply placing legal bets at licensed sportsbooks and taking advantage of publicly available odds. No federal or state law prohibits shopping for the best odds and betting accordingly. However, sportsbooks can limit or close your account if they determine you are not a profitable customer for them.

Can you get banned or limited for arbitrage betting?

Yes. While not illegal, arbitrage betting is unprofitable for sportsbooks, and they reserve the right to limit accounts. Common consequences include reduced maximum bet limits, removed promotional offers, and account closure. This happens without violating any law. Sportsbook terms of service give them discretion over which bets they accept and from whom. Account limits are a business reality for successful arb bettors.

What bankroll do you need for arbitrage betting?

You can start with $1,000-$2,500 spread across 3-5 sportsbook accounts. Smaller bankrolls work but generate minimal absolute profit because arbs typically yield 1-3 percent ROI per opportunity. With $1,000 in play, a 2 percent arb returns $20. Larger bankrolls of $10,000+ allow you to capture meaningful profit from each opportunity and maintain balances across more books. Capital efficiency matters because funds locked in one account cannot be used for arbs at another.

What is the difference between 2-way and 3-way arbitrage calculators?

A 2-way calculator handles markets with two outcomes, such as point spreads, totals, and moneylines where ties are not possible or push. A 3-way calculator handles markets with three outcomes, primarily soccer 1X2 (home, draw, away) and NHL regulation-time moneylines. Using the wrong mode produces incorrect stakes. For 3-way arbs, you must bet all three outcomes to lock in guaranteed profit. Missing one outcome means you are exposed to loss if that outcome occurs.