Expected value calculator

Expected value is what a bet makes on average if you could place it over and over. Enter the odds on offer and how likely you think the bet is to win.

Odds on offer Your win probability or your fair oddse.g. a no-vig price Stake

Expected profit

–

per dollar staked

Break-even win rate

–

Your edge

–

your win % minus break-even

How it works

The formula

EV = stake × (win probability × decimal odds − 1). A $100 bet at +110 (2.10) that wins 50% of the time: 0.50 × 2.10 − 1 = +0.05, so +$5 per bet on average, +5% of stake.

Break-even win rate

The win rate where EV is zero: 1 ÷ decimal odds, the bet's implied probability. At -110 it's 52.4%; at +200 it's 33.3%. A bet is only +EV if it wins more often than that.

Where the probability comes from

EV is only as good as the win probability you put in. A common estimate is a sharp market's no-vig price (see the no-vig calculator); a model's rating, like SharpModels', is another. Type a probability or fair odds; each fills in the other.

EV isn't a sure thing

A +5% bet still loses about half the time. EV describes the long run over many bets, and small edges take a lot of bets to show through. To size bets, see the Kelly calculator.

More calculators

All calculators →

Parlay calculatorOdds and payout for a parlay of up to 15 legs, with pushes. Round robin calculatorEvery parlay in a round robin: how many bets, the risk and the payout. Bet payout calculatorWhat a bet pays at American odds, or what to risk to win a set amount. Odds converterAmerican, decimal and fractional odds and implied probability. No-vig fair odds calculatorTake the vig out of a market: fair odds, fair win % and the hold. Hedge calculatorHow much to bet on the other side to lock in a profit or get your stake back. Kelly criterion calculatorHow much of your bankroll the Kelly criterion says to bet. Arbitrage calculatorStakes across two or three prices that pay the same whatever happens. Closing line value calculatorHow the odds you took compare with the closing line. Prediction market calculatorAny prediction market price as odds after its fee, next to a sportsbook's.

For information only: check every figure with your sportsbook or exchange before you bet. Calculators can't make a bet a good one, and only bet what you can afford to lose.