Guide to Accumulator Betting
Accumulator bets, commonly known as accas, are one of the most popular bet types in horse racing. They allow punters to combine multiple selections into a single bet, with the returns from each winning selection rolling onto the next. The appeal is obvious: small stakes can produce substantial returns if all selections win. However, accumulators come with higher risk because every single selection must win for the bet to pay out.
Many bookmakers offer acca insurance promotions, where they refund your stake as a free bet if just one leg of your accumulator loses. These offers typically require minimum odds per selection (usually evens or higher), a minimum number of legs (commonly 4+), and may have a maximum refund cap. Always check the terms and conditions, as qualifying criteria vary significantly between operators.
How Accumulators Work
An accumulator works by multiplying the odds of each selection together. Your stake is placed on the first selection, and if it wins, the total returns (stake plus profit) are automatically rolled onto the second selection. This process continues through every leg of the accumulator. If all selections win, you receive the total accumulated returns. If any single selection loses, the entire bet is lost.
The simplest way to calculate potential returns is to convert all odds to decimal format, multiply them together, and then multiply by your stake. For example, four selections at decimal odds of 2.00, 3.00, 1.50, and 4.00 would give combined odds of 2.00 x 3.00 x 1.50 x 4.00 = 36.00. A £10 stake would return £360, of which £350 is profit.
4-Fold Accumulator Example
The table below shows how a £10 4-fold accumulator builds through each leg, demonstrating the rolling nature of the returns.
| Leg | Horse | Odds (Fractional) | Odds (Decimal) | Running Returns |
|---|---|---|---|---|
| 1 | Selection A | 2/1 | 3.00 | £30.00 |
| 2 | Selection B | 6/4 | 2.50 | £75.00 |
| 3 | Selection C | Evens | 2.00 | £150.00 |
| 4 | Selection D | 5/2 | 3.50 | £525.00 |
Types of Multiple Bets
While the term "accumulator" is often used broadly, different types of multiple bets have specific names based on the number of selections. The table below compares the most common types, showing example returns from a £10 stake at average odds of 2/1 per selection.
| Bet Type | Selections | Number of Bets | Example Returns (£10 stake, all 2/1) |
|---|---|---|---|
| Double | 2 | 1 | £90 |
| Treble | 3 | 1 | £270 |
| 4-Fold | 4 | 1 | £810 |
| 5-Fold | 5 | 1 | £2,430 |
| 6-Fold | 6 | 1 | £7,290 |
Calculating Your Returns
To calculate accumulator returns, convert all fractional odds to decimal odds by dividing the first number by the second and adding one. For example, 5/2 becomes (5 divided by 2) plus 1 equals 3.50. Then multiply all the decimal odds together and multiply by your stake. This gives your total return including your original stake. Subtract the stake to find your profit.
Our Betting Calculator can help you work out potential returns quickly and accurately, including for each-way accumulators which involve more complex calculations.
Managing Risk
The biggest risk with accumulators is that one losing leg wipes out the entire bet. To manage this risk, consider the following strategies. First, limit the number of legs. A 4-fold is far more achievable than a 10-fold, and the returns from a well-selected 4-fold can still be very attractive. Second, focus on shorter-priced selections where you have genuine confidence, rather than loading up on longshots that are unlikely to all win.
Third, consider using related multiple bets like Lucky 15s or Yankees instead of straight accumulators. These bets include singles, doubles, and trebles alongside the accumulator, meaning you can still generate a return even if not all selections win. They cost more in total stake but provide a safety net. Finally, set a strict budget for accumulator betting and treat it as entertainment rather than a primary betting strategy. The long-term expected value of accumulators is lower than singles betting due to the compounding of the bookmaker's margin across multiple selections.
Dead Heats in Accumulators
Dead heats occur when two or more horses finish in an exact tie and cannot be separated. In a dead heat, your stake for that leg is divided by the number of horses involved in the dead heat. If your horse dead-heats with one other, your effective stake is halved. The accumulator then continues at the reduced stake through the remaining legs. This can significantly diminish your potential returns, even when all selections technically win or place.
Void Legs
A leg of your accumulator can be voided for several reasons, most commonly when a horse is declared a non-runner. When a leg is voided, it is simply removed from the accumulator and the remaining legs continue as a reduced multiple. A 5-fold becomes a 4-fold, a 4-fold becomes a treble, and so on. The void selection's odds are removed from the calculation entirely, so your potential returns are reduced accordingly.
Abandoned meetings, walkovers, and certain rule violations can also result in void legs. If all but one leg of your accumulator is voided, the bet settles as a single at the odds of the remaining selection. It is worth checking your bookmaker's specific rules on void legs, as some operators have slightly different policies regarding when and how voids are applied to multiple bets.
Frequently Asked Questions
What is the minimum number of selections for an accumulator?
What happens if one leg of my accumulator is void?
How do dead heats affect accumulators?
Are accumulator bets good value?
What is acca insurance?
Explore our Types of Bets guide for a complete overview of all bet types, or check our daily Accumulator Tips.