Guide
Accumulator bets explained
Updated 12 November 2026 · 3 min read
An accumulator joins several bets into one: every leg must win, and the odds multiply. Four legs at 1.40 pay 3.84. But the chances multiply too: four legs that are each 70 % likely all win only 24 % of the time, and the bookmaker's margin is charged on every leg, so the more legs, the more an accumulator costs you.
How an accumulator works
An accumulator, also called a parlay or a multiple, joins two or more selections into one bet. Every selection, or leg, must win. If one loses, the whole bet loses. In return the odds are multiplied together, so a small stake can win a large return.
| Leg | Odds |
|---|---|
| 1 | 1.40 |
| 2 | 1.40 |
| 3 | 1.40 |
| 4 | 1.40 |
| Accumulator | 1.40 × 1.40 × 1.40 × 1.40 = 3.84 |
A stake of 10 on this accumulator returns 38.40 if all four win: a profit of 28.40.
The chances multiply too
The odds are not the only thing that multiplies. Suppose each leg is 70 % likely. All four win only if each one does: 0.70 × 0.70 × 0.70 × 0.70 = 0.24, or 24 %. Four bets that each win seven times in ten win together less than once in four.
| Legs | Each leg 70 % likely | Each leg 60 % likely |
|---|---|---|
| 1 | 70 % | 60 % |
| 2 | 49 % | 36 % |
| 3 | 34 % | 22 % |
| 4 | 24 % | 13 % |
| 5 | 17 % | 8 % |
| 6 | 12 % | 5 % |
The margin multiplies as well
Every price carries the bookmaker's margin. In a single bet you pay it once; in an accumulator you pay it on every leg. If each leg gives away about 5 %, four legs together give away about 18 %, because (1 ÷ 1.05) to the power of 4 is 0.82. That is why bookmakers promote accumulators so heavily.
A worked example: four legs that are each really 70 % likely, which is a fair price of 1.43, but priced at 1.40. The accumulator pays 3.84 and wins 24 % of the time, so each 1 staked returns 0.24 × 3.84 = 0.92 on average: a loss of about 8 %. A single bet at 1.40 on one of those legs loses only 2 %.
When an accumulator makes sense
As entertainment, with a small stake you do not mind losing. Not as a way to make money: a bet with no value does not get any by being combined with others, and an accumulator can only have value if every leg does. The accumulator builder multiplies the chances and the prices of the legs you pick, so you can see both numbers before you stake.
Staking on accumulators
- Stake less than on a single bet, because the chance of winning is so much lower.
- Fewer legs are better: two or three, not eight.
- Check that each leg has value on its own before you combine it with others. Implied probability and fair price shows how.
- Never use an accumulator to win back a loss. Bankroll management explains why.
Questions
How do you calculate accumulator odds?
Multiply the decimal odds of every leg. Three legs at 1.50, 2.00 and 1.80 give 1.50 × 2.00 × 1.80 = 5.40.
What happens if one leg of an accumulator is void?
Usually the leg is dropped and the accumulator is paid on the remaining legs, as if that selection had odds of 1.00. The bookmaker's rules say exactly what happens.
Is an accumulator a good bet?
Only if every leg has value. The bookmaker's margin is paid on every leg, so the more legs an accumulator has, the more it costs on average.
Why do accumulators lose so often?
Because every leg must win, and the chances multiply: four legs that are each 70 % likely win together only 24 % of the time.
Read next
- Bankroll management and the Kelly criterion
How to size bets: what a bankroll and a unit are, how the Kelly criterion works with a worked example, and why we suggest a quarter of Kelly on our tips.
- Implied probability, fair price and value
How to turn betting odds into a probability, take out the bookmaker's margin to find the fair price, and work out the value in a bet, with worked examples.
See today’s football tips and the other guides. You must be 18 or over. Betting carries the risk of losing money: only stake what you can afford to lose, and see responsible gambling if it stops being fun.