Parlay odds combine multiple selections into one price. The calculation is simple, but interpreting the result requires separating payout math from probability quality.
Last reviewed: 2026-08-10
Combined odds and payout
Multiply decimal odds across every leg. A 1.80 leg and a 2.10 leg produce combined decimal odds of 3.78. Multiply that result by stake to estimate total return, including the original stake.
Probability is a different input
Odds imply a break-even probability, while your estimated probability represents a forecast. Multiplying leg probabilities gives a baseline only when the outcomes are reasonably independent.
Correlation changes the picture
Two selections from the same event can depend on the same match script. A simple product can therefore overstate the true hit rate. Treat same-game and overlapping markets as correlated unless a validated model supports another assumption.
Step-by-step workflow
- 1Convert every price to decimal odds.
- 2Multiply the decimal prices.
- 3Multiply the result by stake for payout.
- 4Assess probability and correlation separately.
Frequently asked questions
Do parlay odds add or multiply?
Decimal odds multiply across legs.
Why does adding one leg reduce hit rate?
Every leg must settle successfully, so the joint probability is lower than the probability of each individual leg.