Free tool
Accumulator Calculator
Doubles, trebles and accas up to six legs. Enter your odds, mark any non-runners, and see your return — plus what the same selections would pay as a full-cover bet.
How an accumulator is priced
An accumulator multiplies the decimal odds of every leg together. Four selections at 2.00 gives you 2 × 2 × 2 × 2 = 16.00, so a £10 stake returns £160. One leg losing takes the whole thing to zero.
Use the bet type dropdown above to pick your number of legs: Double for two, Treble for three, and the full-cover options for four, five and six selections. The calculator shows the accumulator alongside every smaller combination, so you can see at a glance what covering the same selections would cost.
Why the margin compounds
This is the part worth understanding before adding another leg. Every price a bookmaker offers has a margin built into it — the odds are slightly shorter than the true chance of the event. On a single bet you pay that margin once. On an accumulator you pay it on every leg, and the effect multiplies.
A typical football market carries around 5% margin. On a single that is a 5% disadvantage. On a five-fold, compounding across all five legs, the effective margin is closer to 23%. That is why long accas feel like they never land: the potential return looks enormous precisely because the odds have been shaved five times over.
Acca insurance and bonus offers exist because bookmakers know this. They are marketing spend against a bet that already has a large built-in edge.
Non-runners shorten the acca
Mark any leg void and it settles at odds of 1.00 rather than removing your bet. A four-fold with one non-runner becomes a treble at the remaining prices, and your stake stays on it. That is how bookmakers settle withdrawn runners and suspended football matches, and it is the case most people work out wrongly on the back of a betting slip.
Decimal, fractional or evens
Enter odds however they appear on your slip. 2.50, 6/4, 6-4 and evens all work and are converted for you. Accumulator maths is easier in decimal, which is why the breakdown table shows the multiplication rather than the fractions.
The more legs you add, the worse the value gets. This calculator will tell you what an acca returns; it will not make it a good bet. 18+ only. Please gamble responsibly.
Turning acca offers into guaranteed profit
Acca insurance and price boosts are exactly the promotions matched bettors target — not by hoping the acca lands, but by covering it on an exchange so the offer pays either way.
