Accumulator Calculator
Calculate acca odds, returns, and effective margin
Enter Odds (2 Legs)
Decimal odds only (e.g., 1.85, 2.00)
Enter at least 2 valid odds to see margin.
How Margins Compound: The Accumulator Tax
Each leg carries a bookmaker margin (typically 5%). As legs multiply, so does the house edge. This table shows why accumulators are mathematically worse than singles.
| Bet Type | Legs | Effective Margin | Risk Level |
|---|---|---|---|
| Single | 1 | 5.00% | Low |
| Double | 2 | 9.75% | Low |
| Treble | 3 | 14.26% | Medium |
| 4-Fold | 4 | 18.55% | Medium |
| 5-Fold | 5 | 22.62% | High |
| 6-Fold | 6 | 26.49% | High |
| 7-Fold | 7 | 30.17% | Very High |
| 8-Fold | 8 | 33.66% | Very High |
An 8-fold accumulator often carries the same house edge as a slot machine spin. The bookmaker wins more from your acca than from eight separate singles.
Accumulator vs Singles: The Math
Same five picks. Same confidence. Different strategies. See which costs you more in the long run.
| Strategy | Total Stake | Expected Return | Expected Loss |
|---|---|---|---|
| 5 Singles | ₹500 | ₹475 | -₹25 (5%) |
| 5-Fold Acca | ₹100 | ₹77 | -₹23 (23%) |
The acca looks cheaper (₹100 vs ₹500 staked), but you lose a higher percentage of your stake. Over time, singles preserve more bankroll.
Correlation Warning
If your selections are from the same match (e.g., "Kohli 50+ runs" and "India to win"), they are correlated. Bookmakers price this in. Your real probability is lower than this calculator assumes. Most bookmakers do not allow true accumulators on related contingencies - they require a "Bet Builder" tool with adjusted odds.
Want Insurance? Consider System Bets
System bets (Lucky 15, Yankee, Patent) cover multiple combinations so one losing leg does not kill your entire bet. The trade-off: they cost significantly more (a Yankee is 11 bets, not 1). They can reduce variance but do not improve expected value. For most bettors, flat singles remain the best approach.
Frequently Asked Questions
What is an accumulator bet?
An accumulator (also called acca, parlay, or combo bet) combines multiple selections into one bet. All selections must win for the bet to pay out. The odds multiply together, creating larger potential returns but lower probability of winning.
How do accumulator odds work?
Combined odds = Leg 1 × Leg 2 × Leg 3... Example: Three legs at 1.80, 2.00, and 1.50 = 1.80 × 2.00 × 1.50 = 5.40 combined odds. A ₹100 stake returns ₹540 if all three win.
Why are accumulators bad value?
Bookmaker margins compound with each leg. A single bet might have 5% margin. A 5-fold acca compounds to ~23% margin. You are paying exponentially more "tax" to the bookmaker as legs increase.
What is the effective margin on an accumulator?
Effective margin shows the total house edge on your acca. Formula: 1 - (1 - single margin)^legs. With 5% margin per leg: 2-fold = 9.75%, 5-fold = 22.6%, 8-fold = 33.7%. This is why bookmakers promote accas heavily.
Should I bet accumulators or singles?
Mathematically, singles are always better value. The same picks as singles have lower total margin. Accas are entertainment bets with worse expected value. Professional bettors rarely use them.
What is a parlay calculator?
A parlay calculator is the American term for an accumulator calculator. Parlay (US) = Accumulator (UK/India) = Combo bet. This tool works for all formats.