Sports betting arbitrage exists when the best available prices across all outcomes imply less than 100% total probability. This calculator computes the arb percentage, stake split, per-leg payout, and the resulting P/L from the displayed prices.
Calculator · Free
Arbitrage math, stake split included.
Enter the best price for every outcome and a total stake. The calculator checks whether the implied probability sum is below 100%, then allocates stake across legs.
Market inputs
Outcome 1
Outcome 2
Add the best available price for every outcome in the same market. The calculator allocates stake so each winning outcome targets the same gross payout.
Arbitrage exists
+5.000%
Guaranteed profit $50.00 on $1,000.00
| Outcome | Decimal odds | Stake | Payout |
|---|---|---|---|
| Outcome 1 | 2.1000 | $500.00 | $1,050.00 |
| Outcome 2 | 2.1000 | $500.00 | $1,050.00 |
Show your work
Step 1 - implied probability sum
Outcome 1: 1 / 2.1000 = 47.619%
Outcome 2: 1 / 2.1000 = 47.619%
r = 0.952381
exists = r < 1 = true
Step 2 - arbitrage percentage
arbPct = ((1 - r) / r) * 100
= 5.000%
Step 3 - stake split
Outcome 1: stake = $1,000.00 / (2.1000 * 0.952381) = $500.00
Outcome 2: stake = $1,000.00 / (2.1000 * 0.952381) = $500.00
Step 4 - guaranteed profit
min payout = $1,050.00
profit = min payout - total stake = $50.00Arbitrage FAQ
What is sports betting arbitrage?
Sports betting arbitrage is a price mismatch across books where every outcome can be covered and the equalized payout is higher than the total stake.
How is the arbitrage percentage calculated?
Convert each leg to implied probability, sum those probabilities, then compute ((1 - r) / r) * 100. A positive value means the combined prices create an arb.
Why might an arb disappear before you place both legs?
Lines can move, markets can suspend, and books can reject or limit part of the stake. The math is a snapshot of the prices entered into the calculator.
The board is live. Bring a real tool.
7-day free trial · card required · cancel anytime. Founding rates lock for life on the first 50 members.