Accumulator calculator.
Add every selection in your acca, set your stake, and this free accumulator calculator multiplies the odds to show your combined price, total returns and profit, and the real chance the bet lands. It takes decimal, fractional or American odds, and every leg must win for the acca to pay. US bettors call the same bet a parlay. The guide below covers folds, each-way accas and acca insurance.
Build your acca
LiveTotal returns
160.00
profit 150.00
Every selection must win for the acca to pay. This works out a win accumulator; for each-way, see the section below. Calculations run in your browser; nothing is stored. For entertainment, not betting advice.
The short answer
What is an accumulator (acca)?
An accumulator, or acca, is a single bet that combines several selections, where every one must win for the bet to pay. The odds of each leg multiply together, so the returns can be large from a small stake, but one losing leg and the whole acca is gone. It is the same bet a US bettor calls a parlay.
How to use this calculator
Choose your odds format, enter the odds for each selection, and add your stake. Use Add selection for more legs, up to twelve, and Remove to drop the last one. The calculator multiplies the legs into one combined price and shows your total returns, profit, and the chance the full acca lands.
A four-fold at evens (2.00 each) turns a 10 stake into 160 of returns, a 150 profit, but only a 6.25% chance of landing. That is the accumulator trade-off in one line: big returns, long odds.
The math
How accumulator returns are calculated.
It is multiplication. Take the decimal odds of each selection, multiply them all together, then multiply by your stake. That is your total return.
Get every selection into decimal odds. Fractional 5/2 is 2.5 plus the stake, so 3.5; evens (1/1) is 2.0. The calculator converts for you if you enter fractional or American.
Multiply the decimals of every leg. A five-fold at 1.5, 1.8, 2.0, 1.6 and 2.2 multiplies to 19.01.
Multiply that by your stake for the total return, then subtract the stake for profit. A 10 stake on that five-fold returns 190.08, a profit of 180.08.
For the chance of winning, divide 1 by the combined decimal odds. 1 divided by 19.01 is 5.26%, the implied probability the whole acca lands.
Folds
Doubles, trebles and folds.
The number of selections gives the acca its name. A double is two, a treble is three, then it is counted in folds. Here is each one at evens (2.00 a leg) on a 10 stake.
| Bet | Selections | Returns on 10 | Chance |
|---|---|---|---|
| Double | 2 | 40.00 | 25.00% |
| Treble | 3 | 80.00 | 12.50% |
| Four-fold | 4 | 160.00 | 6.25% |
| Five-fold | 5 | 320.00 | 3.13% |
| Six-fold | 6 | 640.00 | 1.56% |
Win and place
Each-way accumulators.
An each-way acca is really two bets: a win acca and a place acca, so your stake is doubled. The place part pays at a fraction of the odds (often 1/4 or 1/5) if your selection finishes in the places.
Take a single each-way bet to see how the place part works, then picture it across an acca. A 10 each-way bet on a 9/1 selection (decimal 10) with 1/5 place terms stakes 20 in total. The place odds are a fifth of the 9 profit plus the stake, which is 2.8. If it wins, you collect the win part of 100 and the place part of 28, for 128. If it only places, you collect the 28.
In an each-way acca, every leg has to at least place for the place part to pay, and every leg has to win for the win part to pay. Because the place odds are smaller, the place return is far lower than the headline win figure. This calculator works out the win accumulator; for each-way, double your stake and treat the place part as a separate acca at the reduced odds.
One leg short
What is acca insurance?
Acca insurance is a bookmaker offer that refunds your stake if just one leg of your accumulator lets you down.
Many books offer it on accas of five or more legs: if exactly one selection loses and the rest win, you get your stake back, usually as a free bet, sometimes as cash, up to a cap. It softens the sting of a single leg spoiling an otherwise winning ticket.
It is a genuine bit of value on bigger accas, but read the terms: the minimum number of legs, the minimum odds per leg, whether the refund is cash or a free bet, and the maximum refund. Insurance does not change the odds your acca pays; it only cushions a near miss by one leg.
Same bet, different name
Accumulator, acca or parlay?
They are the same bet, several selections combined where all must win. The name depends on where you are.
Accumulator and acca (UK and Ireland)
The standard British and Irish term, usually shortened to acca. A four-fold or five-fold just means a 4 or 5 selection acca, priced in decimal or fractional odds.
Parlay (United States)
The US and Canadian word for the exact same bet, usually shown in American odds. A 4-leg parlay is a four-fold acca by another name.
The math is identical
Whatever it is called, you multiply the odds of every selection, then by your stake. This calculator takes decimal, fractional and American, so it works either side of the Atlantic.
Before you bet
An honest word on accas.
Accas are popular for good reason: a few quid can return a tidy sum, and following a Saturday football coupon is good fun. But the math is plain. Every extra selection multiplies the bookmaker margin and shrinks your chance of winning, so over time acca bettors lose faster than single-bet bettors.
This calculator is here to show you exactly what an acca returns and how likely it is, so you can size a bit of fun sensibly. It cannot make you a winner; nothing can. Bet only what you can afford to lose, and if it stops being fun, free confidential help is at BeGambleAware.org.
Questions
Accumulator questions.
What is an accumulator bet (acca)?
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An accumulator, or acca, is one bet combining several selections, where every selection must win for it to pay. The odds multiply together, so the returns are bigger than a single bet, but one losing leg loses the whole acca. US bettors call it a parlay.
How are accumulator returns calculated?
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Convert each selection to decimal odds, multiply them all together, then multiply by your stake. A four-fold at 2.0 each multiplies to 16.0, so a 10 stake returns 160, a profit of 150. Divide 1 by the combined odds for the chance of winning.
How many selections have to win?
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All of them. An acca only pays if every selection wins. If even one loses, the whole bet loses, unless you have acca insurance that refunds your stake when just one leg fails. That all-or-nothing rule is why accas pay so well and land so rarely.
What is an each-way accumulator?
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An each-way acca is two bets in one: a win acca and a place acca, so your stake is doubled. The place part pays at a fraction of the odds, often 1/4 or 1/5, if your selections finish in the places. Every leg must at least place for the place part to return.
What is acca insurance?
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Acca insurance is a bookmaker offer, usually on accas of five or more legs, that refunds your stake if exactly one selection loses and the rest win. The refund is often a free bet up to a cap. Always check the minimum legs, minimum odds and refund terms.
What is the difference between an accumulator, an acca and a parlay?
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None, they are the same bet. Accumulator is the UK and Irish term, acca is its nickname, and parlay is the US and Canadian word. The odds and returns are worked out in exactly the same way, which is why this calculator covers all three odds formats.
What is a four-fold or five-fold?
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It is simply the number of selections in the acca. Two is a double, three a treble, and from four upwards it is counted in folds: a four-fold has 4 selections, a five-fold has 5, and so on. All of them must win for the bet to pay.
About the developer
Jean Borg
Jean builds and maintains every calculator on freecalculators.pro from Malta, with a focus on tools that are fast, free and show their working. This accumulator calculator uses standard odds multiplication and the figures are verified for accuracy. It is provided for education and entertainment, not as betting advice. Please bet responsibly. Page last updated June 2026.