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Free 2-Way and 3-Way Arbitrage Betting Calculator

Enter the best decimal odds available for every outcome and a total stake. The calculator checks the combined implied probability, splits the stake for an equal theoretical return, and shows whether the quoted prices form an arbitrage.

Calculator only. Prices can move, limits can apply, and the final result may differ if every leg is not accepted at the entered odds.

Arbitrage stake calculator

Arbitrage available

Combined implied probability: 96.40% · Theoretical profit margin: 3.84%

Outcome 1 stake$50.59Return $103.70
Outcome 2 stake$49.41Return $103.70

Total theoretical return: $103.70 · Theoretical profit: $3.70

Before acting: confirm every selection covers the same event, market, period and settlement rules. A full-time market, draw-no-bet market and overtime-inclusive market are not interchangeable.

How the arbitrage calculator works

Decimal odds can be converted to implied probability by dividing 1 by the odds. For two outcomes at 2.05 and 2.10, the combined implied probability is:

(1 ÷ 2.05) + (1 ÷ 2.10) = 0.963995, or 96.40%

When the total is below 100%, the entered prices produce a theoretical arbitrage before execution effects. The equal-return stake for each outcome is its implied probability divided by the combined probability, multiplied by the total stake.

Stake i = total stake × (1 ÷ odds i) ÷ combined implied probability

The profit-on-stake percentage is (1 ÷ combined probability − 1) × 100. This is slightly different from simply calculating 100% − combined probability.

See the full formula, worked examples and rounding guide.

2-way versus 3-way arbitrage

2-way marketsCommon examples include tennis match winner, over/under totals and markets where a draw is not a possible settled outcome.
3-way marketsCommon examples include football full-time home/draw/away. All three quoted outcomes must use matching settlement rules.

The calculator accepts decimal odds because they show the total return per unit staked. If your source uses another odds format, convert it before comparing markets.

Why the displayed result is not a guarantee

  • Odds can change between calculation and acceptance.
  • A bookmaker may limit or reject part of the intended stake.
  • Different market names can hide different settlement rules.
  • Rounding stakes can make the returns slightly unequal.
  • Voids, errors, account restrictions, delays and fees can change the outcome.

Use the output as a calculation aid, then independently verify each market. Read common arbitrage betting mistakes and a pre-bet checklist.

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