Implied Probability Calculator

How to use it

1. 1 Choose "I have odds" and pick the format your sportsbook uses, or choose "I have a probability".
2. 2 Type the odds (for example -110) or the percentage (for example 60).
3. 3 Read the probability, the chance the bet loses and the matching odds in the other formats.

What implied probability tells you

Implied probability is the chance of winning that a price needs to be correct for you to break even over many bets. If a bet pays +150, you only come out ahead in the long run if it wins more than 40% of the time. That is why it is also called the break-even win rate.

Compare it with your own estimate. If you think a team wins 55% of the time and the odds imply 48%, the price is better than your estimate says it should be. If you think 45%, the price is worse.

Why the numbers add up to more than 100%

Sportsbook odds include the book's cut, loosely called the vig or juice. Add the implied probabilities of both sides of a typical -110 / -110 market and you get 104.76%, not 100%. That 4.76% above 100% is the overround. The share of the money staked that the book keeps when bets are balanced, called the hold, is 4.55% (1 minus 1 / 1.0476). A single implied probability from posted odds is therefore a little higher than the chance the book itself believes.

To see the chance with the vig removed you need both sides of the market. The No-Vig Calculator does that.

Worked example

Enter -110 with the American format selected. The implied probability is 52.38%, because you risk 110 to win 100: 110 divided by 210. That is the same as "1 in 1.91", and the chance of losing at that price is 47.62%.

Switch to "I have a probability" and enter 60. The fair odds are 1.667 in decimal, -150 in American and 2/3 in fractional.

The formula

Frequently asked questions