Implied Probability Calculator: Odds to Percentage
Every betting line tells you more than you might think. The odds on any wager contain an implied probability, which is the win percentage you need to hit just to break even at those prices. Our implied probability calculator instantly converts American, decimal, and fractional odds into win percentages, helping you understand what the sportsbook thinks will happen and whether you might have an edge.
This guide shows you how to use the calculator, explains the math behind odds-to-probability conversion, and teaches you how to apply implied probability to find value bets, strip out the vig, and make sharper betting decisions across NFL, NBA, MLB, and beyond.
Implied Probability Calculator: Convert Odds to Win Percentage
Use the implied probability calculator below to convert any betting odds into a win percentage. Enter your odds in American, decimal, or fractional format and instantly see the implied probability and break-even win rate.
This odds converter calculator powers the implied probability conversion. Enter your odds in the format your sportsbook displays, and the calculator will show you the implied probability as a percentage. This is your break-even win rate, meaning you need to win at least this often for the bet to be profitable over time.
How to interpret your results:
The implied probability tells you what percentage of the time you need to win for the bet to break even. For example, if you enter -110 American odds, you will see an implied probability of roughly 52.4%. This means you need to win more than 52.4% of your bets at -110 to make money long-term.
Key features of this calculator:
- Instant conversion: Enter odds and see the implied probability immediately with no page reload
- Multiple formats: Works with American odds (plus/minus), decimal odds, and fractional odds
- Mobile-friendly: Check implied probability from your phone while comparing lines at different sportsbooks
- Live betting ready: Quick enough to use during in-play betting when odds are moving fast
Remember that implied probability includes the bookmaker's margin (vig). The percentage you see represents what the book thinks the probability is, plus their built-in profit. This is not a guarantee of what will happen, but rather a starting point for your own analysis.
For a deeper understanding of how this calculator works, see our complete odds converter guide which explains every input and output in detail.
How to Use the Implied Probability Calculator Step by Step
Converting odds to implied probability takes just a few seconds. Here is exactly how to use the calculator:
Step 1: Choose your odds format
Select whether you are entering American odds (the default for US sportsbooks), decimal odds, or fractional odds. Most US bettors will use American odds, which display as positive or negative numbers like +150 or -200.
Step 2: Enter your odds
Type in the odds exactly as they appear on your sportsbook. For American odds, include the plus or minus sign. For decimal odds, enter the number with decimals (like 2.50). For fractional odds, enter as a fraction (like 3/1).
Step 3: Read your implied probability
The calculator instantly shows the implied probability as a percentage. This is your break-even win rate at those odds.
Worked examples:
Example 1: Standard -110 line
You are looking at a point spread priced at -110. Enter -110 in the calculator, and you will see an implied probability of approximately 52.38%. This means you need to win about 53 out of every 100 bets at -110 to turn a profit.
Example 2: Underdog at +200
You find an underdog priced at +200. Enter +200 in the calculator, and the implied probability shows 33.33%. The sportsbook is pricing this outcome at roughly a 1-in-3 chance. If you think the true probability is higher than 33.33%, this could be a value bet.
Example 3: Heavy favorite at -300
A heavy favorite is listed at -300. The calculator shows an implied probability of 75%. You need to be very confident this team wins more than 3 out of every 4 times to consider this a good bet.
When to use the calculator:
Use this tool every time you are evaluating a bet. Before placing any wager, check the implied probability to understand what win rate you need. This is especially valuable when comparing the same bet across different sportsbooks to see which book offers better odds (lower implied probability on the side you want to bet).
Betting Odds Probability Calculator Use Cases
The implied probability calculator applies to virtually every bet type you will encounter at US sportsbooks:
Moneyline bets: The most direct application. Convert the moneyline odds to see exactly what chance the book is giving each team.
Point spreads: Most spreads are priced near -110 on both sides, meaning roughly 52.4% implied probability. When you see -105 or +100, the implied probability drops, potentially indicating value.
Totals (over/under): Same logic as spreads. Convert the odds on your over or under selection to understand the book's assessment.
Player props: Props often have more varied pricing. Use the calculator to quickly evaluate whether +140 on a player rushing over 75 yards represents genuine value based on your research.
Futures: Longshot futures like +2500 to win the Super Bowl translate to just 3.8% implied probability. Understanding these small percentages helps you assess whether a futures bet makes sense.
Live betting: Odds move fast during games. The calculator helps you quickly assess in-play opportunities before the lines shift again.
For detailed instructions on converting between odds formats manually, see our complete odds conversion guide.
What Is Implied Probability in Sports Betting?
Implied probability is the conversion of betting odds into a percentage that represents the likelihood of an outcome according to the sportsbook's pricing. When a sportsbook sets odds on a game, those odds reflect what the book believes (or wants you to believe) about each outcome's chances, plus their built-in profit margin.
A simple definition:
Implied probability answers the question: If these odds were fair, how often would this outcome need to happen for the bet to break even?
For example, if a team is listed at -150, the implied probability is about 60%. The sportsbook is pricing that team as having roughly a 60% chance to win (though the true probability might be different once you remove the vig).
Why implied probability matters:
Understanding implied probability transforms how you evaluate bets. Instead of thinking in terms of odds alone (which can be confusing), you can think in percentages. Most people intuitively understand that a 60% chance is better than a 40% chance. Converting odds to probability lets you compare your own assessment of an outcome against what the market is pricing.
For a comprehensive explanation of the theory behind implied probability, read our guide on implied probability in sports betting.
How sportsbooks use implied probability:
Sportsbooks set their odds based on a combination of statistical models, historical data, expert opinions, and market demand. The resulting implied probabilities reflect the book's assessment of each outcome, but with extra margin (vig) built in to guarantee the book profits over time.
The key insight:
Implied probability is your break-even benchmark. If you can consistently identify situations where your estimated probability exceeds the implied probability, you may have found value that can lead to long-term profits.
Odds vs Probability: Why They Are Not the Same Thing
Odds and probability describe the same underlying concept, likelihood of an outcome, but they are expressed differently and serve different purposes.
Odds represent price:
When you see -150 or +200, you are looking at a price. The odds tell you how much you can win relative to your stake. They are the sportsbook's way of expressing value in terms that determine payouts.
Probability represents chance:
Probability is expressed as a percentage from 0% to 100%. It directly answers the question: How likely is this outcome?
A simple analogy:
Think of a fair coin toss. The true probability of heads is 50%. But if a sportsbook offered you -110 on heads and -110 on tails, the implied probability of each side would be about 52.4%. The extra 2.4% on each side represents the vig, the price of playing.
Fair odds vs actual odds:
Fair odds would give you exactly 50% implied probability on a true coin flip, meaning +100 (even money) on each side. Sportsbooks rarely offer fair odds because they need to make money. The gap between fair odds and actual odds is where the book profits.
Understanding this distinction helps you see that every bet starts at a disadvantage. Your job as a bettor is to find situations where your edge overcomes that built-in house advantage.
How to Convert Betting Odds to Implied Probability (Formulas for Every Odds Type)
While the calculator handles conversions instantly, understanding the formulas helps you verify calculations and deepen your knowledge of betting math. Each odds format has its own conversion formula.
The formulas are straightforward once you see them in action. You do not need to memorize them since the calculator does the work, but knowing how the math works builds confidence in your betting decisions.
For a complete manual conversion guide, see How to Convert Odds: Complete Guide.
American Odds to Percentage Formula
American odds use positive and negative numbers, requiring two different formulas:
For negative American odds (favorites):
Implied Probability = Absolute Value of Odds divided by (Absolute Value of Odds plus 100), then multiply by 100 to get a percentage.
Example: -110 odds
Take the absolute value: 110. Divide 110 by (110 + 100) = 110 divided by 210 = 0.5238. Multiply by 100 to get 52.38%.
Example: -200 odds
Absolute value: 200. Calculate 200 divided by (200 + 100) = 200 divided by 300 = 0.6667. That is 66.67% implied probability.
For positive American odds (underdogs):
Implied Probability = 100 divided by (Odds plus 100), then multiply by 100.
Example: +150 odds
Calculate 100 divided by (150 + 100) = 100 divided by 250 = 0.40. That is 40% implied probability.
Example: +300 odds
Calculate 100 divided by (300 + 100) = 100 divided by 400 = 0.25. That is 25% implied probability.
| American Odds | Implied Probability | Interpretation |
|---|---|---|
| -500 | 83.33% | Heavy favorite |
| -300 | 75.00% | Strong favorite |
| -200 | 66.67% | Moderate favorite |
| -150 | 60.00% | Slight favorite |
| -110 | 52.38% | Standard vig line |
| +100 | 50.00% | Even money |
| +150 | 40.00% | Moderate underdog |
| +200 | 33.33% | Clear underdog |
| +300 | 25.00% | Significant underdog |
| +500 | 16.67% | Longshot |
| +1000 | 9.09% | Major longshot |
Decimal Odds to Implied Probability
Decimal odds are simpler to convert. The formula is:
Implied Probability = 1 divided by Decimal Odds, then multiply by 100.
Example: 1.50 decimal odds
Calculate 1 divided by 1.50 = 0.6667. That is 66.67% implied probability.
Example: 2.00 decimal odds
Calculate 1 divided by 2.00 = 0.50. That is 50% implied probability (even money).
Example: 3.50 decimal odds
Calculate 1 divided by 3.50 = 0.2857. That is 28.57% implied probability.
| Decimal Odds | Implied Probability | American Equivalent |
|---|---|---|
| 1.20 | 83.33% | -500 |
| 1.50 | 66.67% | -200 |
| 1.91 | 52.36% | -110 |
| 2.00 | 50.00% | +100 |
| 2.50 | 40.00% | +150 |
| 3.00 | 33.33% | +200 |
| 4.00 | 25.00% | +300 |
Decimal odds are common in international markets and some US odds comparison tools. The odds converter handles conversions between formats automatically.
Fractional Odds to Implied Probability
Fractional odds appear as ratios like 3/1 or 1/2. The formula is:
Implied Probability = Denominator divided by (Numerator plus Denominator), then multiply by 100.
Example: 3/1 odds (three to one)
Calculate 1 divided by (3 + 1) = 1 divided by 4 = 0.25. That is 25% implied probability.
Example: 1/2 odds (one to two)
Calculate 2 divided by (1 + 2) = 2 divided by 3 = 0.6667. That is 66.67% implied probability.
Example: 5/1 odds (five to one)
Calculate 1 divided by (5 + 1) = 1 divided by 6 = 0.1667. That is 16.67% implied probability.
| Fractional Odds | Decimal Equivalent | Implied Probability |
|---|---|---|
| 1/5 | 1.20 | 83.33% |
| 1/2 | 1.50 | 66.67% |
| 1/1 (evens) | 2.00 | 50.00% |
| 3/2 | 2.50 | 40.00% |
| 2/1 | 3.00 | 33.33% |
| 5/1 | 6.00 | 16.67% |
| 10/1 | 11.00 | 9.09% |
Fractional odds are traditional in UK and European horse racing but less common at US sportsbooks. If you encounter them, use the odds converter calculator to quickly translate to American odds and implied probability.
Moneyline to Probability: US Sports Examples (NFL, NBA, MLB)
American odds dominate US sportsbooks for NFL, NBA, and MLB betting. Here is how implied probability applies to real-world moneyline scenarios across major sports.
NFL Example: Typical Sunday matchup
Consider a game where the Chiefs are listed at -180 and the Raiders are +155:
- Chiefs -180: Implied probability = 64.29%
- Raiders +155: Implied probability = 39.22%
Notice that 64.29% + 39.22% = 103.51%. The extra 3.51% is the sportsbook's vig. According to these odds, the Chiefs have roughly a 64% chance to win, but you need them to win more often than that to profit at -180.
NBA Example: Heavy favorite
In an NBA game, the Celtics might be -350 while the Wizards are +280:
- Celtics -350: Implied probability = 77.78%
- Wizards +280: Implied probability = 26.32%
Total: 104.10% (vig of 4.10%). The Celtics are priced as having nearly a 78% chance to win. If you believe the Wizards have a better than 26% chance (maybe due to injuries or rest factors), the +280 could offer value.
MLB Example: Pitching matchup
In baseball, starting pitchers heavily influence the line. If the Dodgers are -200 with their ace on the mound and the Rockies are +170:
- Dodgers -200: Implied probability = 66.67%
- Rockies +170: Implied probability = 37.04%
Total: 103.71%. The Dodgers are given a 2-in-3 chance to win. MLB moneylines often have more variance than other sports, making implied probability analysis particularly valuable.
Comparing odds across sportsbooks:
| Sportsbook | Favorite Odds | Implied Probability | Underdog Odds | Implied Probability |
|---|---|---|---|---|
| Book A | -165 | 62.26% | +145 | 40.82% |
| Book B | -155 | 60.78% | +135 | 42.55% |
| Book C | -170 | 62.96% | +150 | 40.00% |
If you want to bet the favorite, Book B at -155 (60.78% implied) offers better value than Book C at -170 (62.96% implied). You need a lower win rate to break even at Book B.
Futures and big events:
Super Bowl futures show how implied probability works with longshots:
- Chiefs +400 to win Super Bowl: 20% implied probability
- Lions +1200: 7.69% implied probability
- Panthers +10000: 0.99% implied probability
These small percentages help contextualize longshot bets. A +10000 ticket needs to hit just 1% of the time to break even, but the book is pricing it as having less than 1% true probability.
Odds to Probability Table and Break-Even Win Rate Chart
This reference table shows common American odds with their implied probabilities and break-even win rates. Use it alongside the calculator for quick checks.
Understanding break-even win rate:
The break-even win rate tells you exactly how often you need to win to make money at those odds. At -110, you need to win 52.38% of your bets. If you can identify bets where your true win rate exceeds the break-even rate, you have found an edge.
| American Odds | Implied Probability | Break-Even Win Rate | Wins Needed per 100 Bets |
|---|---|---|---|
| -500 | 83.33% | 83.33% | 84 |
| -400 | 80.00% | 80.00% | 80 |
| -300 | 75.00% | 75.00% | 75 |
| -250 | 71.43% | 71.43% | 72 |
| -200 | 66.67% | 66.67% | 67 |
| -175 | 63.64% | 63.64% | 64 |
| -150 | 60.00% | 60.00% | 60 |
| -130 | 56.52% | 56.52% | 57 |
| -120 | 54.55% | 54.55% | 55 |
| -115 | 53.49% | 53.49% | 54 |
| -110 | 52.38% | 52.38% | 53 |
| -105 | 51.22% | 51.22% | 52 |
| +100 | 50.00% | 50.00% | 50 |
| +105 | 48.78% | 48.78% | 49 |
| +110 | 47.62% | 47.62% | 48 |
| +120 | 45.45% | 45.45% | 46 |
| +130 | 43.48% | 43.48% | 44 |
| +150 | 40.00% | 40.00% | 40 |
| +175 | 36.36% | 36.36% | 37 |
| +200 | 33.33% | 33.33% | 34 |
| +250 | 28.57% | 28.57% | 29 |
| +300 | 25.00% | 25.00% | 25 |
| +400 | 20.00% | 20.00% | 20 |
| +500 | 16.67% | 16.67% | 17 |
| +750 | 11.76% | 11.76% | 12 |
| +1000 | 9.09% | 9.09% | 10 |
| +2000 | 4.76% | 4.76% | 5 |
| +5000 | 1.96% | 1.96% | 2 |
Key benchmarks to remember:
- -110: The standard vig line. You need 52.38% accuracy (about 53 wins per 100 bets).
- +100: Even money. Win half your bets to break even.
- +200: Need to win 1 in 3 bets to break even.
- +1000: Need to hit just 1 in 11 to break even, but these longshots rarely offer true value.
What percentage is -110 odds? Exactly 52.38%. This is the most important number for spread and total bettors to internalize since most bets are priced near -110.
Implied Probability, True Probability, and Vig (Bookmaker Margin)
Here is where betting math gets more sophisticated. Implied probability as we have discussed includes the sportsbook's vig. To find what the market really thinks about an outcome, you need to remove that vig and calculate true probability.
What is vig (juice)?
Vig (short for vigorish, also called juice) is the sportsbook's commission built into every line. It is how the book guarantees profit over time regardless of outcomes. The standard -110/-110 line illustrates this perfectly.
How vig affects implied probability:
At -110, each side has 52.38% implied probability. Add both sides: 52.38% + 52.38% = 104.76%. This exceeds 100% by 4.76%, and that extra percentage is the vig.
In a fair market with no vig, a true 50/50 proposition would be priced at +100 on each side (50% + 50% = 100%). The sportsbook's margin forces bettors to overcome worse odds.
Why Implied Probabilities Add Up to More Than 100%
When you add up the implied probabilities of all outcomes in a market, the total will exceed 100%. This overround (the amount over 100%) represents the bookmaker's built-in profit.
Example: Two-outcome market
| Outcome | Odds | Implied Probability |
|---|---|---|
| Team A | -110 | 52.38% |
| Team B | -110 | 52.38% |
| Total | 104.76% |
The 4.76% overround is the vig. In reality, only one team will win (100% total probability), but the book prices it as if both teams winning were 104.76% likely.
Example: Three-outcome market (soccer or props)
| Outcome | Odds | Implied Probability |
|---|---|---|
| Home Win | +120 | 45.45% |
| Draw | +250 | 28.57% |
| Away Win | +180 | 35.71% |
| Total | 109.73% |
Here the vig is 9.73%, which is higher than a typical two-way market. Markets with more outcomes or less betting volume often carry higher vig.
Removing the Vig to Find True Probability
To estimate true probability, you normalize the implied probabilities so they add up to 100%. This removes the vig and shows you what the market actually believes about each outcome.
Simple normalization formula:
True Probability = Implied Probability divided by Total Implied Probability
Example using -110/-110:
- Total implied: 52.38% + 52.38% = 104.76%
- Team A true probability: 52.38% divided by 104.76% = 50%
- Team B true probability: 52.38% divided by 104.76% = 50%
After removing vig, the market sees this as a true 50/50 game.
Example with uneven odds:
Say Team A is -150 (60%) and Team B is +130 (43.48%), with a total of 103.48%:
- Team A true probability: 60% divided by 103.48% = 57.98%
- Team B true probability: 43.48% divided by 103.48% = 42.02%
The market truly estimates Team A at about 58% and Team B at about 42%.
For automated vig removal and true odds calculations, use our Vig and True Odds Calculator.
Using Implied Probability to Find Value and Positive EV Bets
This is where implied probability becomes a betting weapon rather than just a curiosity. Value betting is the practice of finding bets where your estimated probability exceeds the implied probability, giving you positive expected value (+EV).
What is value betting?
A value bet exists when the true probability of an outcome is higher than the implied probability suggested by the odds. If you can consistently identify and bet these situations, you will profit over time even if you lose some individual bets.
The value equation:
Your estimated probability greater than implied probability = potential value
Example: Finding value
You have researched an NFL game and believe the Raiders have a 38% chance to win. The sportsbook offers +200 on the Raiders, which represents 33.33% implied probability.
Your estimate (38%) exceeds the implied probability (33.33%), suggesting value. This does not mean the Raiders will win, but if you could bet this situation hundreds of times, you would expect to profit.
Example: No value
Same game, but the Raiders are now +150 (40% implied probability). Your 38% estimate is lower than what the book implies. This is not a value bet since the odds do not compensate you enough for the risk.
Expected value (EV) explained:
Expected value calculates the average profit or loss per bet over time. The formula accounts for your win probability and the odds.
Positive EV (+EV) means you expect to profit over many bets at those odds. Negative EV means the house has the edge.
From Implied Probability to Expected Value
To move from implied probability to expected value, you need three things:
- Your estimated probability of winning
- The odds offered (which give you the payout)
- Your stake
The EV formula in plain terms: (Win probability times profit if you win) minus (lose probability times stake if you lose).
Conceptual example:
Bet: $100 on Raiders at +200 Your estimated win probability: 38% Your estimated lose probability: 62%
If you win: You profit $200 If you lose: You lose $100
EV = (0.38 times $200) minus (0.62 times $100) = $76 minus $62 = +$14
The expected value is +$14 per $100 bet. Over many similar bets, you would expect to average $14 profit per bet.
Why EV matters more than individual outcomes:
A single bet either wins or loses completely. But EV thinking trains you to make the right decisions repeatedly. A +EV bet that loses was still the right bet to make. Over hundreds of bets, +EV decisions compound into profits.
Use our Expected Value Calculator to plug in your estimates and see the EV for any bet.
Using Implied Probability for Parlays, Same Game Parlays, and Futures
Implied probability helps evaluate multi-leg bets and long-term futures. The math gets more complex, but the principles remain the same.
Parlay probability basics:
In a parlay, you multiply the individual probabilities of each leg to get the combined hit rate. This shows just how hard parlays are to win.
Example: 2-leg parlay
- Leg 1: -110 (52.38% implied)
- Leg 2: -110 (52.38% implied)
Combined probability: 0.5238 times 0.5238 = 0.2744 or 27.44%
Even a simple two-leg parlay of standard -110 bets has only about a 27% chance to hit.
Example: 3-leg parlay
- Leg 1: -150 (60%)
- Leg 2: -110 (52.38%)
- Leg 3: +120 (45.45%)
Combined: 0.60 times 0.5238 times 0.4545 = 0.1429 or 14.29%
About a 1-in-7 chance to hit all three legs.
| Parlay Legs | Individual Implied Prob | Combined Probability |
|---|---|---|
| 2-leg (-110 each) | 52.38% | 27.44% |
| 3-leg (-110 each) | 52.38% | 14.37% |
| 4-leg (-110 each) | 52.38% | 7.53% |
| 5-leg (-110 each) | 52.38% | 3.95% |
Same game parlay (SGP) caution:
SGPs combine multiple outcomes from a single game. The simple multiplication of probabilities often underestimates true difficulty because legs are correlated.
For example, if you bet a team to win by a large margin AND the total to go over, these outcomes are positively correlated. The book knows this and adjusts the SGP payout downward. Simple probability multiplication does not capture these correlations.
Read our same game parlay guide for deeper analysis of SGP math and strategy.
Futures implied probability:
Super Bowl and March Madness futures show how implied probability applies to longshots:
- Chiefs +400: 20% implied
- Bills +800: 11.11% implied
- Lions +1500: 6.25% implied
- Panthers +15000: 0.66% implied
These percentages help contextualize what you are buying. A +400 ticket prices the Chiefs at a 1-in-5 shot. A +15000 ticket is pricing a team at about 1-in-150.
For parlay calculations, use the parlay calculator.
Common Mistakes When Using Implied Probability
Even experienced bettors make errors when applying implied probability. Here are the most common mistakes and how to avoid them.
Mistake 1: Confusing positive and negative American odds
The formulas for positive and negative odds are different. Mixing them up produces wildly incorrect probabilities. Always double-check whether your odds are positive or negative before calculating.
Mistake 2: Treating implied probability as true probability
Implied probability includes vig. The actual market-estimated probability is lower after removing the vig. Do not assume the book thinks a -200 favorite has exactly 66.67% chance to win since that number includes their margin.
Mistake 3: Ignoring the vig when evaluating edge
If you estimate a team at 55% and the implied probability is 52.38% (-110), you might think you have a 2.6% edge. But after removing vig, the true market probability might be 50%. Your real edge against fair odds is 5%, which changes your bet sizing and confidence.
Mistake 4: Multiplying SGP probabilities naively
SGP legs are often correlated. Multiplying individual probabilities assumes independence, which is false for related outcomes. Your calculated hit rate will be more optimistic than reality.
Mistake 5: Overreacting to small odds movements
If a line moves from -110 to -115, the implied probability shifts from 52.38% to 53.49%. That is about 1% difference. Do not dramatically change your assessment based on minor line movement unless you have additional information about why the line moved.
Mistake 6: Assuming longshot value
Big plus-money odds are not automatically valuable. A +1000 longshot might look appealing (only need to win 9% of the time), but if the true probability is 5%, you are making a bad bet. Always compare implied probability to your genuine assessment, not just to how attractive the payout looks.
Mistake 7: Not accounting for reduced juice
Some books offer -105 lines instead of -110 on certain markets. The implied probability drops from 52.38% to 51.22%. This matters. Always check if reduced juice is available since it improves your break-even rate.
Frequently Asked Questions
What is implied probability in sports betting?
Implied probability is the conversion of betting odds into a percentage that represents the break-even win rate. It tells you how often you need to win at those odds to neither profit nor lose money over time. For example, -110 odds have an implied probability of 52.38%, meaning you need to win about 53% of your bets at those odds to break even.
How do you convert betting odds to implied probability?
For American odds, use the formulas: For negative odds, divide the absolute value of the odds by (absolute value plus 100). For positive odds, divide 100 by (odds plus 100). The calculator on this page does this instantly. Enter your odds in any format (American, decimal, or fractional) and see the implied probability immediately.
What is the formula for American odds to percentage?
For negative American odds: Implied Probability = Absolute Odds divided by (Absolute Odds plus 100) times 100. For positive American odds: Implied Probability = 100 divided by (Odds plus 100) times 100. Example: -150 becomes 150 divided by 250 times 100 = 60%. Example: +200 becomes 100 divided by 300 times 100 = 33.33%.
Why do implied probabilities add up to more than 100%?
Implied probabilities exceed 100% because sportsbooks build their profit margin (vig) into every line. In a true 50/50 game priced at -110 on each side, each side has 52.38% implied probability. The total is 104.76%, and that extra 4.76% is the sportsbook's vig. This overround guarantees the book profits regardless of the outcome.
How do you remove the vig from odds to find true probability?
To find true probability, normalize the implied probabilities to sum to 100%. Divide each implied probability by the total implied probability of all outcomes. For example, if two sides at -110 have 52.38% implied each (104.76% total), divide 52.38% by 104.76% to get 50% true probability for each side. Use our Vig and True Odds Calculator for automatic no-vig calculations.
How can you use implied probability to find value bets?
Compare your estimated probability of an outcome to the implied probability from the odds. If your estimate is higher than the implied probability, you may have found a value bet with positive expected value. For example, if you believe a team has a 40% chance to win and the odds imply only 33%, that could be value. Consistently betting +EV spots leads to long-term profits.
What percentage do I need to win to break even at -110?
At -110 odds, you need to win 52.38% of your bets to break even. This means winning about 53 out of every 100 bets. This is the standard vig line for point spreads and totals at most US sportsbooks. Finding reduced juice (-105 or better) lowers your break-even rate to around 51%.
Can you use implied probability for parlay or same game parlay bets?
Yes, but with caveats. For standard parlays, multiply the implied probabilities of each leg to estimate your hit rate. A 2-leg parlay at -110 each has about 27% combined probability. For same game parlays, simple multiplication underestimates difficulty because legs are often correlated. Sportsbooks adjust SGP payouts to account for correlations, so your actual hit rate is typically lower than simple probability multiplication suggests.
Gamble responsibly. If you or someone you know has a gambling problem, call +1-800-GAMBLER.
