Sports Betting Implied Probability Calculator
Reviewed by Hamza Gujjar, Algorithm Architect & Software Developer
Last updated: July 27, 2026What odds are really saying about probability
Posted betting odds always encode an implied probability - converting odds to this percentage makes it possible to directly assess whether a bet's payout justifies its risk based on your own probability estimate.
Worked example
For decimal odds of 2.50:
Implied Probability = (1 / 2.50) x 100 = 40.0%
Summing implied probabilities across all outcomes of a real sportsbook market will always total more than 100% - the excess above 100% is the bookmaker's built-in margin (vigorish), not a genuine reflection of the true underlying probability of each outcome.