Arbitrage calculator

Add up two opposing prices and see whether they come in under 100%.

Side A odds

Side B odds

Total stake

Stake A

48.84

Stake B

51.16

Payout

107.44

Profit

+7.44

Arbitrage — the two prices imply 93.07% (under 100%). Stake 48.84 on A and 51.16 on B for a guaranteed 7.44 (7.44% ROI) either way.

Enter the best price for each side from different sportsbooks. An arb exists only when the combined implied probability is under 100%.

How arbitrage works

An arbitrage (or “arb”) happens when two sportsbooks price the same market far enough apart that the best price on each side, taken together, implies less than 100%. Split the stake the way the calculator shows and both outcomes return the same amount — more than the total staked, as long as both bets stand at the prices you took.

Arbs are usually small and short-lived, and a stake limit, a voided leg or a line move can erase one before both bets are placed. Treat this as a line-shopping tool: the same best-price habit that surfaces arbs also lowers the margin you pay on every other bet. Log both legs in Bankroll Guardian so your CLV and ROI stay accurate.

More free tools

Bankroll calculatorYour unit size — and how long it survives a cold streak.Kelly criterion calculatorHow much to bet — sized to your edge.Each way calculatorWhat you get back if it wins, if it places — and the price where placing starts to pay.Dutching calculatorSplit a stake so every outcome returns the same — and see whether that certainty is a profit.

Track every bet automatically

Stop doing the math by hand. Bankroll Guardian logs your bets and shows P&L, ROI, CLV and more — free to start, no card required.

Start free See the demo