An acca (accumulator) combines multiple selections into one bet. All legs must win for the acca to return a profit.

How do you calculate combined odds?

Multiply the adjusted decimal odds for each leg. Void selections count as 1.0 and Rule 4 reduces the winning portion of that leg.

How does Rule 4 affect the acca?

Rule 4 reduces the winnings part of a leg. We apply a simple deduction to the odds for that selection before combining the total.

What happens if one leg loses?

If any leg is marked Lost, the accumulator returns zero and the stake is lost.

Can I use fractional odds?

Yes. Switch the odds format to fractional and enter prices as a/b. The calculator converts them to decimal for the total.

Acca Calculator

Build accumulator bets with confidence. Set your unit stake and odds format, then track how results and Rule 4 deductions affect the return.

Model singles through twentyfolds.
Track live return and profit as results change.
Apply Rule 4 deductions without a manual spreadsheet.

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Acca Calculator

Calculate combined odds, implied probability, and returns.

Accumulator bets

Build an accumulator by entering each selection’s odds, result and Rule 4 deduction. Totals update live so you can see the combined return as you tweak the legs.

Unit stake (£)

Type

Odds format

Each way

Selection	Odds	Result	Rule 4

Total stake	Total return	Total profit
£0.00	£0.00	£0.00

How it works

How the acca calculation works

Accumulator rule: all legs must win for a full return. If any leg is marked Lost, the return is £0.
Void legs: treated as odds 1.0 so they do not change the product.
Rule 4: the winning part of a leg is reduced using 1 + (odds − 1) × (1 − rule4).
Fractional odds: convert to decimal as 1 + (a ÷ b).
Total return: unit stake × combined odds, profit is return minus stake.

Always gamble responsibly. This calculator is for information only and does not guarantee profit.

FAQs

How many legs can I add?

Select a type from single up to twentyfold. The table will always match that number of legs.

Do I need decimal odds?

No. You can switch between decimal and fractional formats and the calculator will convert as needed.

How does Rule 4 change the return?

Rule 4 trims the winnings portion of that selection before the total is combined. The higher the deduction, the lower the return.

What about each-way accas?

Each-way accas depend on place terms. This calculator keeps the toggle for reference but shows win returns only.