What is an accumulator bet?

An accumulator (or "acca") is a multi-leg bet where every leg must win for the bet to pay. Stable Bet's calculator covers 4-leg up to 8-leg accumulators. Winnings from each leg roll over to the next, producing eye-catching potential returns — but a single losing leg busts the whole bet.

How many selections can be in an accumulator?

From 4 to 8 in our calculator. Bookmakers technically allow up to 20+ on most platforms, but the chance of all legs winning drops sharply past 6 or 7 — even with 5 legs at evens the all-win probability is only about 3%.

What is acca insurance?

A bookmaker promotion that refunds your stake (often as a free bet) if exactly one leg of your accumulator loses. Common at Bet365, Sky Bet and Paddy Power. Terms vary — usually requires 5+ legs, minimum odds per leg, and the refund is capped.

Does my accumulator pay if one leg loses?

Not directly — the standard acca rule is all legs must win. But if your bookmaker offers acca insurance and your acca meets the qualifying terms, you may get a stake refund as a free bet. If you want a real return when one or two legs lose, use a Lucky 15 (4 selections), Lucky 31 (5) or Lucky 63 (6) instead.

Why are accumulator odds so big?

Because the decimal odds of every leg multiply together. Five horses at 3/1 each = 4.0 ⁵ = 1,024.0 — a £10 stake returns £10,240 if all five win. The big number reflects the very low probability — only about 0.1% chance of all five winning at fair-priced selections.

Accumulator (Acca) Calculator

What is an accumulator?

An accumulator (or 'acca') is a multi-leg bet where every leg must win for the bet to pay out. Winnings from each leg roll over to the next, producing eye-catching potential returns — but a single losing leg busts the whole bet.

How to use it

1Add 4 to 8 selections — all must win for the acca to pay.
2Enter your stake (one unit stake covers the whole acca).
3Many bookmakers offer an acca insurance refund if exactly one leg loses — worth checking before placing.

Read the full accumulator guide

Worked example

Example: 5-fold at evens for £10

Five selections at Evens (decimal 2.0 each). Combined decimal odds 2^5 = 32.0. £10 returns £320 if all five win, £0 if any leg loses. The chance of all five winning is roughly 3.1% (1/32).

Quick scenarios

Tap a preset to fill the form with realistic odds + stake — useful for trying the calculator before entering your own.

Selected legs

5 / 8 selections

Add the horses or selections in your bet. The number of legs you can use depends on the bet type.

Leg 1

Odds