Implied Probability Calculator

How it is calculated

The tool takes decimal odds (also called European odds), which show the total return per 1 unit staked, stake included. The implied probability is P = 100 ÷ odds, printed as a percentage with 2 decimal places. Decimal odds must be greater than 1.00. A value of 1 or less, a negative number and an empty box give no result, because odds of exactly 1.00 would mean a 100 % certainty with no profit. Fractional odds (5/2) and American odds (+250, −150) are not accepted; convert them to decimal first. The figure is the probability the bookmaker's price implies, margin included, and not a fair estimate of the true chance. It handles one outcome at a time and does not strip out the margin.

Common mistakes

• Entering fractional odds such as 5/2 or American odds such as +250. Only decimal odds work; 5/2 is 3.50 in decimal and +250 is also 3.50.
• Confusing profit with return. Decimal odds of 3.40 include your stake back, so the profit is 2.40 per unit, not 3.40.
• Adding implied probabilities of all outcomes and expecting 100 %. Bookmaker margin makes the total higher, so a single result here is slightly too high as a fair probability.
• Treating the output as the real chance of winning. It is only the price's implication; a team can be priced at 29.41 % and truly have 35 % or 25 %.
• Typing odds of 1.00 or less, such as 0.5, and expecting a result. Decimal odds start above 1, so these entries return nothing.