Work out arbitrage betting instantly with clear inputs, formula shown and shareable results.
Stakes are split in proportion to each outcome's implied probability, so the return is identical whichever wins; an arbitrage exists only when the book total is below one. A negative profit here simply means the two prices still carry a combined margin, so there is no arbitrage and the bet should not be placed.
Book total
book = 1 / odds A + 1 / odds B; an arbitrage exists when book < 1
Stake split
stake on A = total x (1 / odds A) / book total
book = 1 / odds A + 1 / odds B; an arbitrage exists when book < 1. Stakes are split in proportion to each outcome's implied probability, so the return is identical whichever wins; an arbitrage exists only when the book total is below one.
A negative profit here simply means the two prices still carry a combined margin, so there is no arbitrage and the bet should not be placed.
Enter best odds on outcome a, best odds on outcome b, total amount to stake. The defaults shown are a realistic worked example — swap in your own figures to get a result you can use.