Expected Value Calculator

Enter the decimal odds, your estimated win chance, and your stake. The calculator shows the expected value per unit, your expected return on the stake, and whether the bet is in your favour.

How to read it

• EV per unit is the headline. Positive means the price is paying more than the risk deserves; negative means it is not.
• Price implies is the chance the odds assume (1 ÷ decimal odds). If your estimate beats it, you have value.
• Return on stake turns the percentage into money for the stake you entered — the average profit or loss per bet, not a guaranteed result.

The formula

EV per unit = (your win probability × decimal odds) − 1

For example, odds of 2.50 with a 50% estimated chance give (0.50 × 2.50) − 1 = +0.25, or +25% per unit.

What the number does and doesn't tell you

A positive result does not mean this bet wins — EV is a long-run average, and any single bet can go either way. It means that if your probability estimate is accurate, repeating this kind of bet makes money over time. The hard part is the estimate: the calculator trusts whatever win chance you type in, so the edge is only real if your number genuinely beats the bookmaker's.

That is exactly what statistical models are for. To understand the idea in full, read Expected Value in Betting; to see model-built probabilities compared to live prices across hundreds of leagues, head to Find Value.