Implied Probability: Convert American Odds Into a Percentage

Implied probability translates a sportsbook price into the break-even win rate associated with that price. It is a starting point, not proof of the outcome's true chance.

Formulas

Positive odds: 100 ÷ (odds + 100). Negative odds: |odds| ÷ (|odds| + 100). For example, +150 converts to 40.0%, −150 converts to 60.0%, and −110 converts to approximately 52.38%.

Why implied is not true probability

Sportsbook prices include margin. In a two-sided market, the implied percentages can add to more than 100%. A fair estimate requires removing margin and choosing representative market prices.

Use the American odds converter

Sources: Legal Sports Report; Investopedia.