Calculate expected value for any bet. Enter the offered odds and your estimated true probability to see if you have an edge.
Expected value (EV) tells you how much a bet is worth on average over time. A positive EV (+EV) bet is profitable in the long run, even if individual bets can lose.
The formula is: EV = (probability × profit) - (1 - probability) × stake. If the bookmaker offers odds of 2.10 but the true probability is 50%, the EV is +5% per bet.
The Kelly Criterion uses your edge to calculate optimal stake size. Full Kelly maximises long-term growth but has high variance. Most professional bettors use half or quarter Kelly for smoother results.