How an Accumulator bet works
The odds of each leg are multiplied together. Four selections at evens (2.00) make 2 × 2 × 2 × 2 = 16.00, so £10 returns £160. That multiplying is why accas look so attractive, and why one losing leg loses the whole bet.
A void or non-runner leg is settled at odds of 1.00 and simply drops out, so a five-fold with one void becomes a four-fold. An each-way acca is two accas: a win acca at full odds and a place acca at the each-way fraction of every leg.
The bookmaker’s margin also multiplies. A margin of around 5% per leg compounds to roughly 28% across a five-fold (1.05 to the fifth power), so the true chance of the acca landing is lower than the combined odds suggest.
How acca odds grow with each leg
| Bet | Prices | Combined odds | Return |
|---|---|---|---|
| 2-fold | 2/1, 3/1 | 12.00 | £120.00 |
| 3-fold | 2/1, 3/1, 5/2 | 42.00 | £420.00 |
| 4-fold | 2/1, 3/1, 5/2, 6/4 | 105.00 | £1,050.00 |
| 5-fold | 2/1, 3/1, 5/2, 6/4, 4/1 | 525.00 | £5,250.00 |
| 6-fold | 2/1, 3/1, 5/2, 6/4, 4/1, 7/2 | 2362.50 | £23,625.00 |
| 7-fold | 2/1, 3/1, 5/2, 6/4, 4/1, 7/2, 9/4 | 7678.13 | £76,781.25 |
| 8-fold | 2/1, 3/1, 5/2, 6/4, 4/1, 7/2, 9/4, 11/8 | 18235.55 | £182,355.47 |
Each extra leg multiplies the odds, and multiplies the chance of a loser too.
Worth knowing
Acca insurance offers, which refund the stake as a free bet if one leg loses, change the maths but not the settlement. The free bet is usually stake-not-returned. Our matched betting calculator shows what that free bet is really worth.
Accumulator questions
How are accumulator odds calculated?
Convert each price to decimal odds and multiply them together. Multiply the result by your stake to get the return, including the stake. For example, 2/1, 6/4 and evens are 3.00, 2.50 and 2.00, giving combined odds of 15.00.
What happens to my acca if a match is postponed?
Most bookmakers void the leg if the match is not played within a set time, typically by the end of the next day. The acca then carries on as a smaller multiple. Rules vary, so check your bookmaker’s terms.