EV Calculator — Expected Value for Betting

Calculate expected value (EV), Kelly Criterion stake sizing, and batch scan multiple bets. Free tool for sports bettors and crypto gamblers.

%
$
+EVResult
+$12.50
Expected Value
+12.5%
EV%
$250.00
Payout
$150.00
Profit

EV Calculator FAQ

What is Expected Value (EV) in betting?

Expected Value (EV) measures the average profit or loss you can expect per bet over the long run. A positive EV (+EV) means the bet is profitable over time. The formula is: EV = (Win Probability × Profit) - (Lose Probability × Stake).

What is the Kelly Criterion and how does it work?

The Kelly Criterion is a mathematical formula that determines the optimal percentage of your bankroll to wager. It balances maximizing growth with minimizing risk of ruin. The formula is: f* = (bp - q) / b, where b is the net odds, p is win probability, and q is lose probability.

Should I use Full Kelly or fractional Kelly?

Most professional bettors use Half Kelly (50%) or Quarter Kelly (25%) to reduce variance and the risk of large drawdowns. Full Kelly maximizes theoretical growth but produces very volatile swings in practice.