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Parlay Calculator: Odds, Payout and Win Probability
Calculate the combined odds, payout and true win probability of any parlay, with the formula and the cost of the vig on every extra leg.
A parlay ties several bets together so that every leg must win, and the payout multiplies with each one. That is the appeal. The catch is that the sportsbook’s margin multiplies too. Enter your legs below to see the combined odds, the payout and the true chance your parlay lands.
The parlay formula
Convert every leg to decimal odds, then multiply them:
Parlay odds = decimal₁ × decimal₂ × … × decimalₙ
Total payout = stake × parlay odds. Profit is the payout minus the stake.
The implied probability of the parlay is 1 ÷ parlay odds. If you have your own probability for each leg, multiply those together to get your true chance of winning.
Worked example: a three-leg NFL parlay
You put $20 on three legs: two spreads at -110 and an underdog moneyline at +150.
| Leg | American | Decimal | Implied probability |
|---|---|---|---|
| Spread A | -110 | 1.909 | 52.4% |
| Spread B | -110 | 1.909 | 52.4% |
| Underdog ML | +150 | 2.500 | 40.0% |
Parlay odds: 1.909 × 1.909 × 2.50 = 9.11. A $20 stake returns $182.23, a profit of $162.23. In American terms that is roughly +811.
The parlay’s implied probability is 1 ÷ 9.11, or 10.97%.
The hidden cost of every extra leg
A -110 spread is really a coin flip with a margin added. If each spread is a true 50% shot, the fair decimal price is 2.00. The sportsbook pays 1.909.
On one bet that costs you about 4.5% of the fair payout. On a two-leg parlay, the fair odds are 4.00 but you get 3.64, about 9% less. On four legs, fair is 16.00 and you get 13.28, about 17% less. The longer the ticket, the more you are paying for the excitement.
That is why same-game parlays and long accumulators are among the sportsbook’s most profitable products. Use the calculator above to see the gap on your own ticket, and compare each leg’s price with the implied probability calculator.
When to use a parlay calculator
- Before you bet: confirm the payout matches the bet slip, since some books round or adjust correlated legs.
- When a parlay boost is offered: compare the boosted payout with the true odds to see whether the boost creates value. Our expected value calculator takes it from there.
- When you are one leg away: work out the current value of the ticket, then use our hedge calculator to decide whether to lock in profit.
- When an AI tool suggests a parlay: check how much margin you are stacking. Our AI betting tools guide covers which tools build parlays and how.
Parlay mistakes that cost bettors money
- Adding legs for a bigger number. Each extra leg lowers your chance of winning and stacks another layer of the sportsbook’s margin onto the price.
- Ignoring correlation. Some same-game legs depend on each other, such as a team winning and its quarterback throwing for big yardage. The book prices them with that link in mind.
- Treating a near miss as close. Losing by one leg pays the same as losing every leg.
- Skipping line shopping. A slightly better price on each leg compounds just as the margin does. The best available odds matter more in a parlay than in a single.
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FAQ
How do you calculate parlay odds?
Convert each leg to decimal odds and multiply them together. The result is your total return per $1 staked. A two-leg parlay at 2.50 and 1.91 has combined odds of 4.775, so $10 returns $47.75.
What does a 3-team parlay pay at -110?
Each -110 leg is 1.909 in decimal. Multiplied three times that is about 6.96, so a $100 parlay returns about $696, a profit of roughly $596, or close to 6-to-1.
What happens if one leg of a parlay pushes?
At most US sportsbooks, a pushed or voided leg is removed and the parlay is recalculated with the remaining legs. Check your sportsbook's house rules, because treatment can vary.
Are parlays a bad bet?
They carry a higher house edge than single bets because the margin on each leg compounds. They are not automatically bad, but you need a genuine edge on several legs to make them worthwhile.