Parlay Calculator
The combined odds of a parlay (accumulator) from up to six legs, the payout for a stake, and the implied probability of every leg landing — with the bookmaker’s margin compounded in.
A parlay wins only if every leg wins, so the decimal odds multiply: three legs at 1.
How the parlay calculator works
A parlay wins only if every leg wins, so the decimal odds multiply: three legs at 1.9, 2.1 and 1.5 pay 5.99 to 1 the stake. The implied probability is 1 divided by the combined odds — but each leg carries the bookmaker’s margin, and multiplying the legs multiplies the margins, which is why parlays are the most profitable bets a bookmaker takes.
Formula: combined odds = o₁ × o₂ × … × oₙ; payout = stake × combined; implied probability = 1 ÷ combined
Worked examples
| Inputs | Combined decimal odds | Note |
|---|---|---|
| 1.9 × 2.1 × 1.5, 10 staked | 5.985 | 5.985 — returns 59.85 |
| Two evens | 4 | 4.0 — returns 80 |
| Six short favorites at 1.25 | 3.815 | 3.815 |
FAQFrequently asked questions
Why are parlays bad value?
Each leg’s odds include a margin of a few percent for the bookmaker. Multiplying four legs multiplies the margins too, so a parlay of 5% margins hands over nearly 20% of the fair payout, against 5% on a single.
What are decimal odds?
The total return per unit staked, stake included: 2.50 returns 2.50 for every 1 staked (1.50 profit). Fractional 3/2 and American +150 are the same price.
What if one leg is a push (void)?
That leg is removed and the parlay stands on the remaining legs at their combined odds — the payout shrinks, but the bet is not lost.
Is the implied probability the real chance?
No — it is what the price implies after the margin, so it overstates the chance. The bookmaker margin calculator shows how much.
Where these figures come from
- World Handicap System — Rules of Handicapping — the score differential and handicap index formula
- International Cricket Council — Playing Conditions — over structure and run-rate definitions
- Major League Baseball — Official Rules — the published definitions for baseball statistics
Last checked: September 2026. Formulas follow the governing bodies where one publishes them — the World Handicap System for golf, the ICC playing conditions for cricket run rates.