Implied Probability Calculator
Convert American odds to implied probability. See the true win percentage the sportsbook is pricing into any line.
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What Is Implied Probability?
Implied probability is the win percentage that betting odds represent. Sportsbooks set odds based on their assessment of the likelihood of an outcome, plus their built-in margin (vig). Understanding implied probability helps you identify value bets — situations where you believe the true probability is higher than what the odds suggest.
The Formula
- Negative odds: Implied probability = |odds| / (|odds| + 100)
- Positive odds: Implied probability = 100 / (odds + 100)
Example
At -150 odds, the implied probability is 150 / (150 + 100) = 60%. The sportsbook is pricing this outcome at a 60% chance of winning. If you believe the true probability is higher — say 65% — then this is a +EV bet.
Frequently Asked Questions
What is implied probability in sports betting?
Implied probability is the likelihood of an outcome as reflected by the betting odds. It converts odds into a percentage that represents how often an outcome would need to win for the bet to break even. Sportsbooks use implied probability to set their lines, and bettors use it to find value.
How do you calculate implied probability from American odds?
For negative American odds, divide the absolute value of the odds by (the absolute value plus 100). For example, -150 gives 150/(150+100) = 60%. For positive odds, divide 100 by (the odds plus 100). For example, +200 gives 100/(200+100) = 33.3%.
Why do implied probabilities from a sportsbook add up to more than 100%?
The implied probabilities of all outcomes in a market add up to more than 100% because the sportsbook includes a margin called the vig or juice. This overround is how the book guarantees a profit. For example, a standard -110/-110 market has total implied probability of about 104.5%, with the extra 4.5% being the vig.
How do you use implied probability to find value bets?
Compare the implied probability from the odds to your own estimated probability for the outcome. If you believe an outcome has a 55% chance of winning but the odds imply only 50%, you have found a value bet with a positive expected value. The bigger the gap between your estimate and the implied probability, the stronger the edge.
Get the Edge with Optimal Bet
Our app scans sportsbook pricing across the market to expose inefficiencies and uncover +EV edges. We compare odds, surface high-value opportunities, and deliver precision alerts so you can move with conviction.
