Betting Tools

EV Calculator

Calculate expected value and ROI from decimal odds and your estimated win probability.

Expected value (EV)
+0.100
Per 1 unit staked
ROI
+10.00%
Return on stake

What is EV (Expected Value)?

Expected value, or EV, is the average profit or loss you should expect per bet if the same edge were repeated many times. Positive EV means the price is in your favor, while negative EV means the bet is overpriced against you.

This calculator combines your estimated win probability with the market odds to show both the EV in stake units and the same edge expressed as ROI. That makes it easier to compare whether a bet is actually worth taking, not just whether it feels likely to win.

EV matters most over a large sample of bets. Any single wager can win or lose because of variance, but consistently taking positive-EV prices is one of the clearest ways to build long-term betting profit.

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