Expected value (EV) calculator

Compute expected value per €1 staked given your odds and the true probability. Positive EV = profitable in the long run.

✓ Positive EV
Fair odds1.92
Edge+9.20%
EV per €1€0.0920
EV on €100 stake€9.20

How it works

EV per stake = (p × (odds − 1)) − ((1 − p) × 1). Multiply by stake for the absolute expected profit.

Step by step

  1. Enter the odds, Decimal, convert with the odds-converter if needed.
  2. Enter your true probability, Use the Polymarket fair line, your model, or the fair-margin median.
  3. Calculate, Positive EV = long-term profitable.

FAQ

What is a good edge?

4-6% is workable, 8%+ is strong. 2% is at the noise floor.

How accurate does my probability need to be?

Within 1-2%. Use Polymarket mid-price or the fair odds calculator for a sharp anchor.