Arbitrage Calculator

An arbitrage exists when the best odds across different bookmakers imply less than 100% combined probability. Cover every outcome with proportional stakes and the return is the same whichever way the game goes.

Enter the best price per outcome and your total stake. The calculator checks the inverse sum, shows the margin, and splits your stake so all outcomes pay the same. The math is exact; the execution risks (moving lines, voided legs, account limits) are covered in the FAQ — read them before treating any arb as money in the bank.

Outcome 1 (best odds)

Outcome 2 (best odds)

Total stake (€)

Σ 1/odds

0.9640

Margin

+3.73%

Locked result

+€3.73

Arbitrage exists at these prices — split stakes as below.

Outcome	Stake	Share
Outcome 1	€49.40	49.4%
Outcome 2	€50.60	50.6%

How to use the Arbitrage Calculator

1
Choose the market type (2-way or 3-way) and enter the BEST decimal odds you can find for each outcome — usually at different bookmakers.
2
Enter the total amount you want to spread across all outcomes.
3
Read the verdict: Σ 1/odds below 1.0 means an arb exists. The table shows the exact stake per outcome so every result returns the same payout.

Worked example

2-way arb: 2.10 at book A, 2.05 at book B

Inverse sum = 1/2.10 + 1/2.05 = 0.964 — below 1.0, so an arb exists with a margin of +3.7%. On a €100 total: stake €49.40 on side A and €50.60 on side B. Either way the payout is €103.74. For comparison, the same market at a single book (1.91 / 1.91) has an inverse sum of 1.047 — no arb, just vig.

FAQ

Arbitrage Calculator FAQ

What is an arbitrage bet (arb)?

An arb exists when the best available odds across different bookmakers imply a combined probability below 100% — formally, when the sum of 1/odds over all outcomes is less than 1. Covering every outcome with proportional stakes then returns more than you staked no matter the result. Arbs appear because books move lines at different speeds and disagree about prices.

How are the stakes split?

Each outcome gets a share proportional to its implied probability: stake_i = total × (1/odds_i) ÷ Σ(1/odds). That makes every outcome pay out the identical amount (total ÷ Σ(1/odds)). The margin — your locked return — is 1 ÷ Σ(1/odds) − 1. A 2-way arb at 2.10 and 2.05 yields about 3.7% on the total stake.

What are the practical risks of arbitrage betting?

The math is risk-free; the execution is not. Main risks: a line moves or a bet is voided after you placed only one side (leaving a naked position), stake limits prevent filling the calculated amounts, odds were stale when you clicked, and — most importantly — bookmakers limit or close accounts that arb them. Palpable-error rules can also void one leg retroactively. Treat the calculated margin as the best case, not a certainty.

Why do most arbs disappear quickly?

An arb is a disagreement between books, and books copy each other's moves within seconds to minutes. The biggest gaps usually involve a stale line that is about to be corrected — which is also why a flagged 'edge' at one slow book often vanishes by the time you reach the bet slip. Speed and access to many books matter more than the math.

BetEdge is an analytics and decision-support tool — not a bookmaker and not a tipster service. We don't accept bets or hold funds. For educational and informational purposes only. 18+.

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