Free tool
Accumulator calculator
Combined odds and returns for any number of legs, and the chance the prices imply.
- Legs counted
- 4
- blank or invalid legs are ignored
- Combined odds
- 11.06
- Total return
- 110.56
- stake included
- Profit if it lands
- 100.56
- Implied chance of landing
- 9.0%
- from the prices, margin included
Every leg carries the bookmaker’s margin, and an accumulator multiplies them: with 4 legs at a typical 5% margin each the book’s edge on the whole bet is roughly 22%. The price looks big because the chance is small.
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The arithmetic
An accumulator pays the product of its legs: the return from the first selection is staked in full on the second, and so on. Converting each leg to a decimal price and multiplying gives the combined price, and the stake times that price is the return. Void legs (a postponed match, a non-runner) are settled at 1.00 and drop out of the multiplication.
Why the price looks big
The combined price is large because the combined chance is small, and the two are not quite inverses: the bookmaker’s margin is in every leg, so the implied probability of the accumulator overstates the true one by the compounded margin. At a 5% margin per leg the book keeps around 10% of a double, 16% of a treble and 22% of a four-fold — before any question of whether the selections are good ones.
That is why value bettors stake singles. A selection with a genuine edge keeps that edge as a single; put it in an accumulator with three selections that have none, and the whole bet is negative expectation.
Questions
- How are accumulator odds calculated?
- Multiply the decimal price of every leg. Four legs at 1.80, 2.10, 1.50 and 1.95 give 1.8 × 2.1 × 1.5 × 1.95 = 11.06, so a 10 stake returns 110.57.
- What is the chance of an accumulator winning?
- The product of the chances of every leg. Four selections that each land 60% of the time land together 0.6⁴ = 13% of the time. The calculator shows the chance the prices imply, which includes the margin and is therefore higher than the true chance.
- Why are accumulators poor value?
- Because every leg carries the bookmaker’s margin and the margins multiply. Four legs at a 5% margin each give the book a 21.6% edge on the whole bet, against about 5% on a single. The bigger the accumulator, the larger the share of the return that is margin.
- Does this site advise accumulators?
- No. Every advised bet is a single, and the record is settled single by single. Combining selections multiplies the margin and the model error alike.
The same numbers on real fixtures
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A calculator turns your numbers into other numbers. It does not know whether your numbers are right, and no arithmetic makes an outcome certain. Never stake money you cannot afford to lose.