How do you calculate a parlay payout?

Convert each leg to decimal odds, then multiply them together to get the parlay's combined decimal odds. Multiply that product by your stake for the total return, then subtract the stake for profit. Example: three legs at -110, +150, and -200 convert to 1.909, 2.500, and 1.500. Multiply: 1.909 x 2.500 x 1.500 = 7.159. A $50 stake returns $357.95 total, or $307.95 profit.

What are the odds of hitting a 5-leg parlay?

At standard -110 juice per leg, each leg carries a true probability around 50%. Five independent 50% events hit simultaneously 3.13% of the time — roughly 1 in 32. Most bettors overestimate their hit rate because they remember wins and forget losses. The implied probability at -110 per leg is even lower at 2.7%, reflecting compounded vig. The gap between 3.13% true and 2.7% implied is margin you pay the sportsbook.

Is a parlay a good bet?

Generally parlays are negative expected value because the vig from each leg compounds multiplicatively. A two-leg parlay at -110/-110 carries roughly double the single-bet vig. The exception is correlated parlays — legs within the same game whose outcomes are statistically linked, such as a moneyline and the game total. If the sportsbook underestimates that correlation, the true combined probability exceeds the independent calculation, creating potential +EV.

Parlay Calculator: Calculate Parlay Odds and Payouts

The parlay calculator above computes combined odds, total payout, and implied probability for any multi-leg wager. Enter each leg’s odds in American, decimal, or fractional format along with your stake amount. The tool multiplies the decimal odds of every leg and returns the parlay price, expected payout, and the true probability of all legs hitting.

How Does the Parlay Calculator Work?

The calculator follows the standard parlay math: convert each leg to decimal odds, multiply all legs together, and apply the stake. The result is deterministic — no modeling or estimation involved.

Step-by-step:

Enter odds for each leg in any format. The calculator converts all inputs to decimal internally.
Enter your stake amount.
The tool outputs: combined decimal odds, equivalent American odds, total payout, profit, and the combined implied probability.

Adding or removing legs updates the calculation instantly. This lets you test how each additional leg changes the payout and the probability of winning.

How Do Payouts and Probability Scale With Legs?

Every leg added to a parlay multiplies the odds — and divides the probability. The table below shows the progression for standard -110 legs, assuming a true 50% win probability per leg.

Legs	Combined Decimal Odds	Payout on $100	True Win Probability	Vig-Adjusted Implied Prob	Cumulative House Edge
2	3.645	$364.46	25.0%	27.5%	9.1%
3	6.962	$696.15	12.5%	14.4%	13.2%
4	13.293	$1,329.27	6.25%	7.5%	17.0%
5	25.382	$2,538.16	3.13%	3.9%	20.5%
6	48.454	$4,845.39	1.56%	2.1%	23.8%

The Cumulative House Edge column reveals why most parlays lose money over time. Each -110 leg adds roughly 4.5% of vig. By leg six, nearly a quarter of your expected return goes to the sportsbook before the games start.

For a full breakdown of why this compounding effect matters, see what is a parlay bet.

How Do You Evaluate Whether a Parlay Has Value?

A parlay is +EV only when the product of your true probability estimates exceeds the combined implied probability from the odds. The calculator shows the implied probability — you supply the true probability from your own analysis.

Worked example: You like three legs:

Leg 1: -150 (implied 60.0%), your estimate: 65%
Leg 2: +120 (implied 45.5%), your estimate: 50%
Leg 3: -110 (implied 52.4%), your estimate: 55%

Combined implied probability: 60.0% x 45.5% x 52.4% = 14.3%

Your combined true estimate: 65% x 50% x 55% = 17.9%

Your estimate exceeds the implied probability by 3.6 percentage points. That gap is your edge — the parlay is +EV by this analysis. If the gap were negative, you would be paying more vig than your edge can overcome.

Use the EV calculator to quantify the dollar value of that edge, the expected value guide for the full framework, and the implied probability guide for the conversion formulas.

How Does the Same Math Apply to Prediction Markets?

Prediction market contracts are priced as direct probabilities. A contract at $0.60 implies 60% — no conversion formula needed. Combining two prediction market positions into a parlay-style trade (both must resolve Yes) works identically: multiply the probabilities.

If Contract A trades at $0.60 and Contract B trades at $0.45, both hitting has a combined probability of 27%. Because prediction markets carry 1-3% in effective spread versus 4-10% vig per sportsbook leg, the compounding cost of a multi-leg position is substantially lower.

The Odds Reference dashboard tracks contract prices across platforms in real time. Cross-referencing prediction market probabilities against sportsbook parlay odds on the same events can surface pricing discrepancies — particularly on correlated outcomes where sportsbook SGP models may lag market-implied correlations.

When Do Correlated Parlays Create Value?

The calculator assumes independent legs — each leg’s probability is unaffected by the others. Correlated parlays violate this assumption in your favor. If two outcomes are positively correlated (both more likely to happen together), the true combined probability exceeds the independent product.

Common correlations:

Team moneyline + game over: Winning teams tend to score, pushing totals higher
QB passing yards + team total: High-scoring offenses generate passing volume
Weather + game under: Rain and wind suppress scoring

If the sportsbook prices these as independent (or underestimates the correlation), the parlay becomes +EV. The calculator gives you the independent baseline; your job is to assess whether correlation shifts the true probability above that line.

Key Takeaways

Parlay math is multiplication: convert legs to decimal odds, multiply together, apply stake
Each -110 leg adds roughly 4.5% house edge — five legs approach 20%+ cumulative vig
A parlay is +EV only when your combined true probability exceeds the combined implied probability
Correlated legs (same-game parlays) are the primary exception where parlays can offer genuine value
Prediction market positions compound with lower friction due to tighter spreads versus sportsbook vig