Implied probability calculator
Convert sportsbook odds into the break-even probability implied by the price. No account, picks, or prediction required.
Reviewed
At -110, the break-even rate before fees or other assumptions is 52.38%.
The formulas
For negative American odds A: |A| / (|A| + 100). For positive American odds: 100 / (A + 100). For decimal odds D: 1 / D. Multiply the result by 100 to express it as a percentage.
| Odds | Calculation | Implied probability |
|---|---|---|
| -110 | 110 ÷ 210 | 52.38% |
| +150 | 100 ÷ 250 | 40.00% |
| 2.50 | 1 ÷ 2.50 | 40.00% |
Why both sides can add above 100%
A sportsbook normally prices margin into a market. If both teams are -110, each side converts to 52.38%, for a total of 104.76%. That excess is often called the overround or vig. To estimate the market's normalized two-way probabilities, use the no-vig calculator.
What the number means
Implied probability is the break-even rate encoded by a price. It is not proof that the event's true probability equals that number, and it does not account for limits, taxes, timing, or execution. Read the full guide to implied probability for interpretation and common mistakes.