Implied Probability Calculator
Convert decimal odds into a percentage, or compare every outcome of a complete market. Free to use without registration.
How to convert decimal odds to probability
Implied probability (%) = 100 ÷ decimal odds. A price of 2.00 implies 50%; 1.80 implies 55.56%; 2.50 implies 40%.
What is overround?
Add the implied probabilities of all mutually exclusive outcomes, then subtract 100%. Two prices of 1.90 imply 52.63% each: a total of 105.26% and an overround of 5.26 percentage points. This is not the bookmaker’s realized profit.
Use a complete market: BTTS Yes and No, Over and Under the same half-goal line, or home, draw and away in 1X2. Do not combine different goal lines, double-chance selections, different bookmakers or prices recorded at different times.
What does normalization mean?
Normalized probability (%) = outcome implied probability ÷ total implied probability × 100. At 1.90 / 1.90 the normalized values are 50% / 50%. At 2.00 / 2.00 the total is already 100% and the overround is zero.
This proportional method removes the mathematical overround. It assumes proportional scaling across outcomes; it does not establish their true chances. It also does not model pushes or partial settlements on integer and quarter-goal lines.
