Odds converter
Enter odds in any format — American, decimal, fractional, or implied probability — and we'll show all four equivalents instantly.
Common conversions
| American | Decimal | Fractional | Implied prob. |
|---|---|---|---|
| -300 | 1.33 | 1/3 | 75.00% |
| -200 | 1.50 | 1/2 | 66.67% |
| -150 | 1.67 | 2/3 | 60.00% |
| -110 | 1.91 | 10/11 | 52.38% |
| +100 | 2.00 | 1/1 | 50.00% |
| +110 | 2.10 | 11/10 | 47.62% |
| +150 | 2.50 | 3/2 | 40.00% |
| +200 | 3.00 | 2/1 | 33.33% |
| +500 | 6.00 | 5/1 | 16.67% |
| +1000 | 11.00 | 10/1 | 9.09% |
See also: implied probability glossary entry.
Odds converter — FAQ
How do you convert American odds to decimal?
Positive American odds: decimal = (american / 100) + 1. So +200 → 3.00. Negative American odds: decimal = (100 / |american|) + 1. So -150 → 1.67.
How do you convert American odds to implied probability?
Positive American: p = 100 / (american + 100). +200 → 33.3%. Negative American: p = |american| / (|american| + 100). -150 → 60%. This is the probability the price implies the outcome has, before vig is removed.
What's the difference between American, decimal, and fractional?
Same odds, different display. American is standard in the US. Decimal is standard in Europe and easier for math (just multiply by stake to get total return including stake). Fractional (5/2, 1/3) is traditional in the UK. All convert losslessly.
Why do most pros prefer decimal odds?
Decimal odds make expected value and Kelly criterion math trivial — multiply stake by decimal odds to get gross return, subtract stake for profit. American odds require branching logic for favorites vs underdogs. For programmatic betting, decimal is the universal format.