Guide
How to calculate parlay odds
A parlay pays by multiplying the price of every leg together. Once you can convert odds to decimal, the whole calculation is three steps — and one honest check at the end that tells you whether the price is worth taking.
1.Convert each leg to decimal odds
Books show American odds, but the math is done in decimal. Positive odds: 1 + (odds / 100) — so +150 becomes 2.50. Negative odds: 1 + (100 / |odds|) — so -110 becomes 1.909.
2.Multiply the decimal prices together
Two legs at -110: 1.909 × 1.909 = 3.645. Add a third leg at +150: 3.645 × 2.50 = 9.112. That single number is the parlay's true combined price.
3.Convert back and multiply by your stake
9.112 decimal is +811 in American odds. A $25 stake returns $227.79 — your $25 back plus $202.79 profit.
4.Run the break-even check
Divide 100 by the combined decimal: 100 / 9.112 = 11.0%. The slip has to land more often than that for the price to be worth it. If your honest estimate of the chance is lower, the payout — however big it looks — is not big enough.
Worked example, start to finish
You like three sides: Chiefs -3 at -110, Ravens moneyline at -110, and a live underdog at +150.
- -110 → 1 + 100/110 = 1.909
- -110 → 1.909
- +150 → 1 + 150/100 = 2.50
- 1.909 × 1.909 × 2.50 = 9.112 (+811)
- $25 × 9.112 = $227.79 back, $202.79 profit
- Break-even: 100 / 9.112 = 11.0%
If the Ravens leg pushes, the book drops it and the slip pays 1.909 × 2.50 = 4.77 — $119.32 on the same $25.
Payout table (all legs at -110)
Standard -110 pricing on every leg, on a $100 stake. Notice how fast the break-even chance falls as legs are added — that is the compounded cost of a long slip.
| Legs | Combined odds | $100 returns | Profit | Break-even chance |
|---|---|---|---|---|
| 2 | 3.64 / +264 | $364.46 | $264.46 | 27.44% |
| 3 | 6.96 / +596 | $695.79 | $595.79 | 14.37% |
| 4 | 13.28 / +1228 | $1328.33 | $1228.33 | 7.53% |
| 5 | 25.36 / +2436 | $2535.91 | $2435.91 | 3.94% |
| 6 | 48.41 / +4741 | $4841.27 | $4741.27 | 2.07% |
Skip the arithmetic
The free parlay calculator does every step on this page for you — type the legs in whatever format the book shows and it returns the combined price, payout, profit and break-even chance instantly.
Common questions
- What is the formula for parlay odds?
- Combined decimal odds = leg 1 decimal × leg 2 decimal × … × leg N decimal. Payout = stake × combined decimal odds. To get American odds from a decimal price of 2.00 or more, use (decimal − 1) × 100; below 2.00, use −100 / (decimal − 1).
- How do I convert American odds to decimal?
- For positive odds like +150: decimal = 1 + (odds / 100), so +150 becomes 2.50. For negative odds like -110: decimal = 1 + (100 / |odds|), so -110 becomes about 1.909.
- Why does the sportsbook payout differ from my calculation?
- Three common reasons: a leg was priced differently than you remembered, a leg pushed and was dropped from the slip, or it is a same-game parlay where the book prices correlated legs jointly instead of by simple multiplication.
- How do I know if a parlay price is fair?
- Divide 100 by the combined decimal odds — that is the break-even win chance. If your own estimate of the slip landing is higher than that number, the price has value; if it is lower, the payout is not big enough for the risk.
- Do pushes count as losses in a parlay?
- At most books, no. A pushed leg is removed and the parlay is paid at the remaining legs' combined price. A two-leg parlay with one push becomes a single bet at the surviving leg's price.
Stratos prices real parlays against live sportsbook markets and grades every published pick in public afterwards. Check the settled record or convert a single price.