Implied probability calculator

Turn any price into the chance it implies. Add the other outcomes of the market to see the bookmaker margin and the fair probability underneath. Free, no account, decimal, American and fractional odds.

Implied probability

Implied probability
52.63%
Decimal
1.900

This is the bookmaker’s probability with its margin still inside. To see the fair probability, enter every outcome of the market with the 2-way or 3-way switch.

How it works

Odds and probability are the same information written two ways. For a decimal price:

implied probability = 1 / decimal odds
  • Decimal 2.50: 1 / 2.50 = 40.00%.
  • American +150 is 2.50 decimal, so also 40.00%. American -110 is 1 + 100 / 110 = 1.909, which implies 52.38%.
  • Fractional 5/2 is 1 + 5 / 2 = 3.50 decimal, which implies 28.57%.

Add up the implied probabilities of every outcome in one market and you get the overround. The amount over 100% is the bookmaker margin. Removing it gives the fair probability; this calculator uses the logarithmic method, which takes more of the margin off the longer price, the same way OddsHub prices every market.

Reading the result

Implied probability is a break-even line, not a forecast. A bet at 2.50 needs to win more than 40% of the time to make money over many bets, and the margin means the bookmaker expects it to win a little less. Comparing that line with a sharper estimate of the true chance is the whole idea behind value bets: the free value bets page compares every bookmaker price with the fair price from a sharp market. To check a single market by hand, the no-vig calculator shows the fair odds, and the EV calculator turns a probability and a price into expected profit.

After the match, the same idea grades your bet: if the odds you took were longer than the fair closing price, you beat the market. Check it with the CLV calculator and the Pinnacle closing odds lookup.

More betting calculators

Calculators show arithmetic, not predictions. No result here guarantees a profit, and betting always carries the risk of losing your stake. Bet only what you can afford to lose; help and limits are on the responsible gambling page.

Frequently asked questions

How do I calculate implied probability from odds?
With decimal odds, divide 1 by the price: 2.50 implies 1 / 2.50 = 40%. American odds are converted first: +150 is 2.50 in decimal, and -110 is 1.909, which implies 52.38%. The calculator does the conversion for you.
Why do the probabilities add up to more than 100%?
Because every bookmaker price includes a margin. Two prices of 1.90 each imply 52.63%, 105.26% together. The 5.26% over 100% is the bookmaker margin, also called the vig or overround.
What is the difference between implied and fair probability?
Implied probability is read straight from the price, margin included. Fair probability is what is left once the margin is removed from every outcome of the market. Switch to 2-way or 3-way to see both side by side.
How does implied probability help me find value?
A price is only worth taking if your estimate of the chance is higher than the implied probability. If you think a team wins 45% of the time and the odds imply 40%, the price is above fair for you. If your estimate is lower, the bet loses money on average.