Expected Value Calculator
Enter a posted American odds line and your own probability estimate for the outcome. This tool strips the market's implied probability out of the odds and tells you whether your number represents a positive expected value.
How this works
Every posted line implies a probability once you strip out the bookmaker's margin. If you believe the true probability of an outcome is higher than what the line implies, the bet has positive expected value (+EV) — over a large enough sample, bets like that are profitable in theory. If your estimate is lower than the market's implied probability, the bet is −EV.
The hard part isn't the math — it's having a probability estimate that's actually more accurate than the market's. This calculator only tells you what a given estimate implies; it doesn't generate the estimate for you.
This tool is for educational purposes and does not constitute betting advice.