Tool · Expected Value
Expected Value (EV) Calculator
An honest probability estimate is the hardest part of betting. This tool just does the math once you have one.
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Market implied
40.00%
Your edge
5.00%
Expected value
$12.50
Kelly fraction
8.33%
Positive EV means the bet would profit on average if your probability is accurate. The Kelly fraction is the theoretically optimal bankroll share - most disciplined bettors stake a quarter or half of it to reduce variance.