Free implied probability calculator

How do you calculate implied probability from betting odds?

Divide 100 by the decimal price. A price of 2.50 implies 100 / 2.50 = 40%. It is the chance the bet needs to win to break even, and it includes the bookmaker's margin, so it is a little higher than the true chance. Type a price in any format below.

Implied probability calculator

Price format

Decimal, like 2.50

Implied probability

40.00%

Break-even win rate

40.0%

One win in about

2.50

Chance it loses

60.00%

A price of 2.50 implies a 40.00% chance, so the bet needs to win more than 40.0% of the time to break even. It is the bookmaker's number including its margin, not the true chance.

18+. Arithmetic on the prices you enter, not a tip or a prediction. Prices can move, and bets can be limited or voided, before both are placed. Gambling Help Online: 1800 858 858.

The live version

BetBank picks compares bookmaker prices with fair chances to list positive EV bets across Australian bookmakers.

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How the calculator works

Implied probability = 100 / decimal price
From fractional n/d: 100 x d / (n + d). From American +A: 100 / (A / 100 + 1); from -A: A / (A + 100) x 100
Break-even win rate = implied probability

Worked example. Decimal 2.50 (3/2, +150) implies a 40.00% chance, so it must win more than 40.0% of the time to make money. American -110 (decimal 1.91) implies 52.38%.

What it assumes. That the price is a single bookmaker's price. The implied chances of every outcome in a market add to more than 100% because of the margin, so an implied probability overstates the true chance: use the no-vig calculator for a fair chance.

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18+. These calculators do arithmetic on the numbers you enter; they are not tips or predictions. Gambling can be harmful. For free, confidential help call Gambling Help Online on 1800 858 858 or visit our responsible gambling page.

Frequently asked questions

What is implied probability?

The chance of an outcome that a betting price represents. It is 1 divided by the decimal price, written as a percentage.

Is implied probability the real chance?

No. It includes the bookmaker's margin, so the implied chances for all outcomes add to more than 100%. Removing the margin gives a fairer estimate, and even that is one bookmaker's opinion.

How do I turn implied probability into odds?

Divide 100 by the percentage. A 25% chance is 100 / 25 = 4.00. The odds converter does it in the other direction too: choose Chance % as the format.

How do I use it to find value?

Compare the implied probability with your own estimate of the chance. If your chance is higher, the price is above your fair price. The EV calculator turns that gap into dollars.