Enter the American betting odds, i.e. +400 or -500, into the calculator to determine the implied probability.

## Implied Probability Formula

The following formula is used to calculate an implied probability.

P- = O / (O+100) * 100

P+ = 100 / (O + 100) * 100

- Where P- is the probability % if the odds are negative
- P+ is the probability % if the odds are positive
- O are the betting odds i.e. +400 or -250 etc.

## Implied Probability Definition

An implied probability is the % chance of success of a bet given the odds displayed by the better. These odds take into account the extra value taken off the top by the betting company, so they may be slightly different than a true chance of the outcome.

## Implied Probability Example

How to calculate implied probability?

**First, determine if the odds are positive or negative.**For this example, we will say the odds are positive. (+ sign in from of the number) .

**Next, determine the odds value.**For this example we will say they are +500.

**Finally, calculate the implied probability.**Using the formula above we find the % of the success of the bet to be 100/(500+100)*100 = 16.66% chance.

## FAQ

**What is implied probability?**

An implied probability is the implied chance of success of a bet given the displayed odds value by the betting company.