Implied probability: turn betting odds into a percentage
To convert decimal odds into price-implied probability, divide 1 by the odds & multiply by 100. This translates the quoted price into a percentage; it does not reveal the true chance of winning.
Convert a price of 2.50
1 ÷ 2.50 = 0.40. Multiply by 100 to get 40%. For a simple cash bet with no fees, that is the break-even win rate at that price over repeated equivalent bets.
| Odds | Price-implied probability |
|---|---|
| 1.50 | 66.7% |
| 2.00 | 50% |
| 2.50 | 40% |
| 4.00 | 25% |
What break-even means
Imagine ten separate €10 bets, all at 2.50, with four wins. The stakes total €100. Four winning returns of €25 also total €100. Profit is zero. This is an arithmetic illustration, not a claim that a particular set of ten bets will produce four wins.
Why the probabilities may add to more than 100%
In a two-outcome market priced at 1.90 on each side, each price converts to about 52.63%. Together they make 105.26%. That excess is the quoted overround. You cannot read both percentages as a complete set of true probabilities.
The useful question is “what percentage does this price imply?” Keep it separate from “how likely is this outcome?”
Sources
Sources checked 2026-09-05. Examples are illustrative unless labelled otherwise.
