Expected Value Calculator
Determine if a bet has positive expected value by comparing the odds you're getting against the true probability. A +EV bet profits over the long run.
Inputs
Your estimated true probability this bet wins
Results
Enter valid odds and probability to see results.
Frequently Asked Questions
What does Expected Value mean in betting?
Expected Value (EV) measures the average profit or loss you can expect per bet over the long run. A +EV bet has a mathematical edge over the sportsbook, meaning it will be profitable over hundreds of wagers even if individual bets lose.
How do I estimate the true probability?
Compare odds across multiple sportsbooks and prediction markets. The sharpest line (lowest vig) gives the best estimate. You can also use power ratings, models, or consensus implied probabilities from our odds comparison tool.
What is the Kelly Criterion?
The Kelly Criterion calculates the optimal bet size to maximize long-term bankroll growth. It balances edge size against odds offered. Most professional bettors use fractional Kelly (e.g. half or quarter) to reduce variance.