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Odds Converter
Decimal, American, fractional, probability: one piece of information, four notations.
Type into any field — the other three update instantly.
Quick conversion table
| Decimal | American | Fractional | Implied probability |
|---|---|---|---|
| 1.20 | −500 | 1/5 | 83.3 % |
| 1.50 | −200 | 1/2 | 66.7 % |
| 1.91 | −110 | 10/11 | 52.4 % |
| 2.00 | +100 | 1/1 | 50.0 % |
| 2.50 | +150 | 3/2 | 40.0 % |
| 3.00 | +200 | 2/1 | 33.3 % |
| 5.00 | +400 | 4/1 | 20.0 % |
| 10.00 | +900 | 9/1 | 10.0 % |
Useful anchor: the famous American −110 (NFL/NBA spread standard) equals 1.91 decimal, i.e. a 52.4% implied probability — the hit rate you must beat to profit on those markets.
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MyBankroll logs your bets in decimal or American odds and computes ROI, CLV and value automatically — by sport, market and bookmaker.
Try MyBankroll free for 7 daysFAQ
How do I convert American odds to decimal?
Positive US odds: decimal = 1 + (US ÷ 100). Example: +150 → 2.50. Negative US odds: decimal = 1 + (100 ÷ |US|). Example: −110 → 1.91. Positive odds show the profit on a 100 stake; negative odds show the stake needed to win 100.
How do I calculate the implied probability of odds?
Implied probability = 1 ÷ decimal odds. Odds of 2.50 imply a 40% chance. Note that the implied probabilities of all outcomes sum above 100% — the excess is the bookmaker's margin (overround), typically 4-7% on main markets.
Why do European bookmakers use decimal odds?
Decimal (European) odds are the norm in continental Europe: they directly show the total return per unit staked (stake included). American odds dominate in the US, fractional in the UK. None is more "correct" — they are three notations of the same probability.
Go further
Informational tool. Implied probabilities include the bookmaker's margin. Gambling involves risk. Please bet responsibly. 18+/21+.