How to Calculate Parlay Odds

Want to calculate parlay odds yourself before placing a bet? Understanding the math behind parlays helps you verify sportsbook payouts, spot value, and make smarter betting decisions. This guide walks you through the complete parlay calculation formula with step-by-step examples for 2-leg, 3-leg, and 4+ leg parlays.

Whether you prefer manual calculations or want to understand what our parlay calculator does under the hood, this guide covers everything from basic multiplication to understanding how juice compounds across multiple legs.

What Are Parlay Odds?

Parlay odds represent the combined probability and potential payout when you link multiple bets together. Unlike straight bets where each wager stands alone, a parlay bet requires every leg to win for you to collect.

This all-or-nothing structure creates the multiplier effect that makes parlays attractive. A 2-leg parlay roughly doubles your potential payout compared to a single bet, a 3-leg parlay roughly triples it, and so on. But calculating the exact odds requires understanding how individual bet odds combine mathematically.

The key insight is that parlay odds multiply together. If you bet two coin flips (each at 2.0 decimal odds), your parlay odds would be 2.0 times 2.0 equals 4.0. This multiplication principle forms the foundation of all parlay calculations.

The Basic Parlay Calculation Formula

The simplest way to calculate parlay odds is using decimal odds. The formula is straightforward:

Parlay Odds = Leg 1 Decimal Odds x Leg 2 Decimal Odds x Leg 3 Decimal Odds x ...

Then to find your total payout:

Total Payout = Stake x Parlay Decimal Odds

And your profit is:

Profit = Total Payout - Stake

Decimal odds already include your stake in the payout, making the multiplication clean. A bet at 2.0 decimal odds means you get back 2 dollars for every 1 dollar wagered (your original dollar plus 1 dollar profit).

This is why experienced bettors convert American odds to decimal before calculating parlays. The math becomes simple multiplication rather than dealing with positive and negative numbers.

Converting American Odds to Decimal

Most US sportsbooks display American odds (like -110 or +150), so you need to convert these to decimal format before calculating your parlay.

For Positive American Odds (+)

Decimal Odds = (American Odds / 100) + 1

Examples:

American Odds	Calculation	Decimal Odds
+100	(100/100) + 1	2.00
+150	(150/100) + 1	2.50
+200	(200/100) + 1	3.00
+300	(300/100) + 1	4.00

For Negative American Odds (-)

Decimal Odds = (100 / |American Odds|) + 1

Note: Use the absolute value of the American odds (ignore the negative sign in the division).

Examples:

American Odds	Calculation	Decimal Odds
-100	(100/100) + 1	2.00
-110	(100/110) + 1	1.909
-150	(100/150) + 1	1.667
-200	(100/200) + 1	1.50
-300	(100/300) + 1	1.333

Converting Fractional Odds to Decimal

If you encounter fractional odds (common in UK markets), the conversion is:

Decimal Odds = (Numerator / Denominator) + 1

Examples:

Fractional Odds	Calculation	Decimal Odds
1/1 (Evens)	(1/1) + 1	2.00
2/1	(2/1) + 1	3.00
5/2	(5/2) + 1	3.50
1/2	(1/2) + 1	1.50
4/5	(4/5) + 1	1.80
10/11	(10/11) + 1	1.909

Note that 10/11 fractional odds are equivalent to -110 American odds, both converting to 1.909 decimal.

Quick Reference Conversion Table

Here are common American odds and their decimal equivalents:

American	Decimal	American	Decimal
-500	1.20	+100	2.00
-400	1.25	+110	2.10
-300	1.333	+120	2.20
-250	1.40	+150	2.50
-200	1.50	+175	2.75
-150	1.667	+200	3.00
-130	1.769	+250	3.50
-120	1.833	+300	4.00
-110	1.909	+400	5.00
-105	1.952	+500	6.00

Step-by-Step: Calculate a 2-Leg Parlay

Let us work through a real example. You want to parlay two NFL moneyline bets:

• Leg 1: Kansas City Chiefs -150
• Leg 2: Buffalo Bills -130

Step 1: Convert to Decimal Odds

Chiefs -150: (100/150) + 1 = 0.667 + 1 = 1.667

Bills -130: (100/130) + 1 = 0.769 + 1 = 1.769

Step 2: Multiply the Decimal Odds

Parlay Odds = 1.667 x 1.769 = 2.949

Step 3: Calculate Payout for Your Stake

For a 100 dollar bet:

Total Payout = 100 x 2.949 = 294.90 dollars

Profit = 294.90 - 100 = 194.90 dollars

Step 4: Convert Back to American Odds (Optional)

To express 2.949 decimal odds in American format:

Since 2.949 is greater than 2.0, use: American = (Decimal - 1) x 100

American Odds = (2.949 - 1) x 100 = +194.9 (typically shown as +195)

You can verify this calculation using our parlay calculator guide which walks through using the calculator for different scenarios.

Step-by-Step: Calculate a 3-Leg Parlay

Now let us add a third leg mixing NFL and NBA:

• Leg 1: Kansas City Chiefs -150 (NFL)
• Leg 2: Buffalo Bills -130 (NFL)
• Leg 3: Los Angeles Lakers +120 (NBA)

Step 1: Convert All Legs to Decimal

Chiefs -150: 1.667 Bills -130: 1.769 Lakers +120: (120/100) + 1 = 2.20

Step 2: Multiply All Three

Parlay Odds = 1.667 x 1.769 x 2.20 = 6.487

Step 3: Calculate Payout

For a 50 dollar bet:

Total Payout = 50 x 6.487 = 324.35 dollars

Profit = 324.35 - 50 = 274.35 dollars

Step 4: American Odds Equivalent

American = (6.487 - 1) x 100 = +548.7 (shown as +549)

Notice how adding just one underdog at +120 significantly boosted the parlay odds from +195 to +549. This demonstrates the multiplier effect of including higher-odds selections.

Step-by-Step: Calculate a 4+ Leg Parlay

For larger parlays, the math stays the same but the numbers get unwieldy. Here is a 4-leg example:

• Leg 1: Chiefs -150 → 1.667
• Leg 2: Bills -130 → 1.769
• Leg 3: Lakers +120 → 2.20
• Leg 4: Yankees -110 → 1.909

Parlay Odds = 1.667 x 1.769 x 2.20 x 1.909 = 12.385

For a 25 dollar bet:

• Total Payout: 309.63 dollars
• Profit: 284.63 dollars
• American Odds: +1139

At this point, manual calculation becomes impractical for quick betting decisions. This is where our parlay odds calculator becomes essential. It handles any number of legs instantly and shows you the exact payout.

Why Manual Calculation Gets Difficult

Beyond 3-4 legs, several factors make manual calculation cumbersome:

1. Decimal precision matters - Rounding 1.909 to 1.91 seems minor, but errors compound across legs
2. Mixed odds formats - Some legs might be in American, others in decimal if comparing across sportsbooks
3. Quick decisions - Live betting parlays require instant calculations
4. Multiple scenarios - Comparing different parlay combinations requires recalculating each time

For serious parlay betting, learn the formula so you understand the math, then use a calculator for actual bets.

Parlay Payout Charts

These charts show typical parlay payouts assuming standard -110 odds on each leg. Real payouts vary based on actual odds, but these provide useful benchmarks.

Standard -110 Legs Payout Chart

Legs	Decimal Odds	American Odds	Payout on 100 Dollar Bet
2	3.65	+265	364.46 dollars
3	6.96	+596	696.07 dollars
4	13.29	+1229	1,329.38 dollars
5	25.37	+2437	2,537.47 dollars
6	48.44	+4744	4,844.03 dollars
7	92.47	+9147	9,247.31 dollars
8	176.54	+17554	17,653.86 dollars
9	337.03	+33603	33,703.30 dollars
10	643.42	+64242	64,341.74 dollars

Mixed Favorites and Underdogs

Including underdogs dramatically increases potential payouts:

Parlay Composition	Approximate Decimal Odds	100 Dollar Payout
3 legs at -110	6.96	696 dollars
2 at -110, 1 at +150	9.12	912 dollars
2 at -110, 1 at +200	10.94	1,094 dollars
1 at -110, 2 at +150	11.93	1,193 dollars
3 at +150	15.63	1,563 dollars

Understanding Parlay Juice (Vig)

Sportsbooks build profit margin (juice or vig) into every bet. For parlays, this juice compounds with each leg, making the effective vig higher than it appears.

How Juice Works on Single Bets

On a standard -110 spread bet, the true odds of a 50/50 event should be +100 (2.00 decimal). The sportsbook offers -110 (1.909 decimal) instead. The difference is their profit margin.

Single bet vig on -110: approximately 4.55%

How Juice Compounds on Parlays

When you parlay two -110 bets, the vig multiplies:

True odds (fair market, no juice): 2.00 x 2.00 = 4.00

Offered parlay odds: 1.909 x 1.909 = 3.644

Effective vig: (4.00 - 3.644) / 4.00 = 8.9%

The vig nearly doubled from 4.55% to 8.9%. Here is how it compounds across more legs:

Number of Legs	Single Bet Vig	Effective Parlay Vig
1	4.55%	4.55%
2	4.55%	8.9%
3	4.55%	13.0%
4	4.55%	16.9%
5	4.55%	20.6%
6	4.55%	24.1%

This compounding vig is why professional bettors generally avoid large parlays. A 6-leg parlay gives the sportsbook nearly a 25% edge before you even consider picking winners.

Calculating Expected Value on Parlays

Expected Value (EV) tells you whether a bet is profitable long-term. For parlays, EV calculation follows the same formula as single bets but uses your parlay odds.

EV Formula

EV = (Win Probability x Profit) - (Loss Probability x Stake)

Or expressed as a percentage of your stake:

EV% = (Win Probability x Decimal Odds) - 1

Example: 2-Leg Parlay EV

Suppose you estimate each leg has a 55% chance of winning (you have a small edge on each).

Combined win probability: 0.55 x 0.55 = 0.3025 (30.25%)

If the parlay pays 3.65 decimal odds:

EV% = (0.3025 x 3.65) - 1 = 1.104 - 1 = +10.4%

This parlay has positive expected value because your edge on each leg multiplied together.

Why Most Parlays Are Negative EV

For the same parlay to be +EV at true 50% probability per leg:

Combined win probability: 0.50 x 0.50 = 0.25 (25%)

EV% = (0.25 x 3.65) - 1 = 0.9125 - 1 = -8.75%

You need to win more than 27.4% of your 2-leg parlays just to break even at -110 odds. Without an edge on the underlying picks, parlays are mathematically losing propositions.

Correlated Parlays

One exception where parlays can offer value is correlated parlays, where the outcomes of your legs are linked. For example, betting a team to win AND the game to go over the total can be correlated if the team tends to win in high-scoring games.

Same game parlays often involve correlated legs, though sportsbooks typically adjust odds to account for obvious correlations.

Use the Parlay Calculator

Rather than doing all this math manually, use our calculator to instantly compute parlay odds for any combination of legs:

How to Use the Calculator

1. Enter your odds - Input the American odds for each leg (-110, +150, etc.)
2. Add legs - Click to add more selections to your parlay
3. Enter your stake - Put in your bet amount
4. View results - See your combined parlay odds, potential payout, and implied probability

The calculator handles all the conversions and multiplication automatically, giving you accurate results in seconds.

Common Calculation Mistakes

Mistake 1: Forgetting to Convert Odds Formats

You cannot multiply American odds directly. -110 times -110 does not equal your parlay odds. Always convert to decimal first.

Wrong: -110 x -110 = 12,100 (meaningless)

Right: 1.909 x 1.909 = 3.644 decimal odds

Mistake 2: Rounding Too Early

Small rounding errors compound across legs. Use at least 3 decimal places during calculations.

Sloppy: 1.91 x 1.91 x 1.91 = 6.97

Accurate: 1.909 x 1.909 x 1.909 = 6.96

The difference grows larger with more legs.

Mistake 3: Confusing "To Win" vs "Total Payout"

Some bettors confuse profit with total payout:

• Profit (to win): What you gain above your stake
• Total payout: Your stake plus profit

On a 100 dollar bet at 3.65 decimal odds:

• Total payout: 365 dollars
• Profit: 265 dollars

Mistake 4: Ignoring Reduced Juice Options

Not all sportsbooks offer the same parlay odds. Some offer reduced juice (-105 instead of -110), which compounds favorably:

3-Leg Parlay	Standard -110	Reduced -105	Difference
Decimal Odds	6.96	7.44	+6.9%
100 Dollar Payout	696	744	+48 dollars

Shopping for the best line on each leg matters even more for parlays.

Parlay Odds by Sport

Different sports have different typical odds ranges, affecting parlay calculations:

NFL Parlays

Most NFL spreads and totals are -110, making calculations straightforward. Moneylines vary more widely, from -500 for heavy favorites to +400 for big underdogs.

Typical 3-leg NFL spread parlay: +596 (6.96 decimal)

NBA Parlays

NBA lines are similar to NFL, with -110 standard on spreads. However, NBA has more games and more public betting, sometimes creating larger line movements.

Tip: Early week NBA lines often have more value than game-day lines.

MLB Parlays

Baseball uses moneylines primarily, creating wider odds ranges. A typical MLB favorite might be -150 to -200, while underdogs range from +130 to +180.

This means MLB parlays have higher variance. Three -150 favorites parlay to just 4.63 decimal odds, while three +150 underdogs parlay to 15.63 decimal odds.

College Sports

College football and basketball often have larger spreads and more mismatches, leading to more extreme moneyline odds. Be cautious parlaying heavy college favorites, as the juice on -400 or -500 moneylines is substantial.

Frequently Asked Questions

How do you calculate a 3-team parlay?

Convert each leg to decimal odds, then multiply all three together. For example, three legs at -110 each: 1.909 x 1.909 x 1.909 = 6.96 decimal odds. A 100 dollar bet would pay 696 dollars total (596 dollars profit).

What is the payout on a 10 dollar parlay at -110 each leg?

For a 2-leg parlay: 10 x 3.65 = 36.50 dollars total (26.50 dollars profit) For a 3-leg parlay: 10 x 6.96 = 69.60 dollars total (59.60 dollars profit) For a 4-leg parlay: 10 x 13.29 = 132.90 dollars total (122.90 dollars profit)

Do all sportsbooks calculate parlays the same way?

Most sportsbooks use true mathematical parlay calculations (multiplying decimal odds). However, some may offer "parlay cards" with fixed payouts that differ from true odds. Some books also offer parlay insurance or boosted parlays with enhanced payouts on specific combinations.

How do pushes affect parlay calculations?

When one leg pushes (ties), most sportsbooks remove that leg and recalculate the parlay with the remaining legs. A 4-leg parlay with one push becomes a 3-leg parlay. Some books may have different push rules, so check your sportsbook terms.

Can I calculate parlays with mixed odds formats?

Yes, but convert everything to decimal odds first. You might have one leg at -110 (American), another at 1.85 (decimal), and a third at 5/6 (fractional). Convert all to decimal, then multiply.

What is the maximum parlay payout?

Most sportsbooks cap parlay payouts, typically between 500,000 and 1,000,000 dollars regardless of calculated odds. Some limit the number of legs (often 10-15 maximum) or restrict certain bet types from parlays.

Are parlay odds the same at every sportsbook?

No. Different sportsbooks may offer slightly different parlay odds for the same legs because they use different odds on individual bets and may have different parlay pricing policies. Shopping across 3-4 books can sometimes find you 5-10% better parlay payouts on the same selections.

How do I calculate a round robin parlay?

A round robin is multiple smaller parlays from a larger set of selections. For example, a 3-team round robin creates three 2-leg parlays. Calculate each 2-leg parlay separately, then add the potential payouts together. The total stake is your per-parlay stake times the number of combinations.

Why do my parlay odds not match the sportsbook exactly?

Minor differences occur due to rounding. Sportsbooks typically round to specific increments (like whole numbers for American odds). Your manual calculation might show +547.8 while the book displays +548 or +545. Differences of more than a few points may indicate an error or the book using non-standard parlay pricing.

Is there a shortcut for calculating parlays with all -110 legs?

Yes. For all -110 legs, you can use these approximate multipliers:

• 2 legs: 3.65x (or about +265)
• 3 legs: 6.96x (or about +596)
• 4 legs: 13.29x (or about +1229)
• 5 legs: 25.37x (or about +2437)

These multipliers work because 1.909 to the power of 2 equals 3.65, to the power of 3 equals 6.96, and so on.

When to Use Manual Calculation vs Calculator

Understanding when to calculate manually versus using a calculator helps you work efficiently while maintaining accuracy.

Use Manual Calculation When:

• Learning the fundamentals - Working through calculations by hand builds intuition about how parlay odds work
• Quick estimates - If you know your legs are all roughly -110, the standard payout chart gives you instant estimates
• Verifying sportsbook math - If something looks off, manual calculation confirms whether the book is correct
• No technology available - At a retail sportsbook without your phone, basic mental math helps

Use a Calculator When:

• Actual betting decisions - When real money is on the line, eliminate human error with a calculator
• Complex multi-leg parlays - Beyond 3 legs, manual calculation becomes error-prone
• Mixed odds formats - Converting American, decimal, and fractional odds simultaneously is tedious by hand
• Comparing scenarios - Testing multiple parlay combinations quickly requires calculator speed
• Live betting - Time pressure during live events demands instant calculations

The ideal approach: understand the formula deeply through manual practice, then use a calculator for all actual bets. This combination gives you both the intuition to spot obvious errors and the precision to avoid costly mistakes.

Key Takeaways

Understanding how to calculate parlay odds empowers you to:

1. Verify sportsbook payouts - Ensure you are getting fair odds
2. Compare across books - Find the best parlay prices
3. Understand the math - See how juice compounds against you
4. Make informed decisions - Know exactly what you are risking for potential reward

The formula itself is simple: convert to decimal, multiply, calculate payout. But the implications are significant. Each leg you add increases your potential payout while also increasing the sportsbook edge against you.

For quick calculations during betting, use our parlay calculator. For understanding why parlays are structured the way they are, the manual method reveals everything.