Odds converter: American, decimal, fractional and implied probability
The same price can be written four ways. American odds (+150, -200) are standard at US sportsbooks, decimal odds (2.50) in Europe, Canada and Australia, and fractional odds (3/2) in the UK. Implied probability (40%) is the common ground for comparing any of them.
Type into any box and the other three update.
How to read odds: Decimal odds show your total return for every $1 wagered. American odds show how much you win (+) or need to bet (-) to win $100. Fractional odds show profit relative to stake. Probability shows the implied chance of the outcome occurring.
Free, no account needed. Everything is worked out in your browser and nothing you type is saved.
How to use the odds converter
- 1Type the odds you have into the matching box: American, decimal, fractional or probability.
- 2The other three fill in as you type.
- 3For American odds include the sign: + for an underdog, - for a favorite.
- 4Use the implied probability to compare prices across formats, or as the win rate the bet needs to break even.
Conversion table for common odds
The prices you will see most often, in every format.
| American | Decimal | Fractional | Implied probability |
|---|---|---|---|
| +250 | 3.50 | 5/2 | 28.57% |
| +150 | 2.50 | 3/2 | 40.00% |
| +110 | 2.10 | 11/10 | 47.62% |
| +100 | 2.00 | 1/1 (evens) | 50.00% |
| -110 | 1.91 | 10/11 | 52.38% |
| -125 | 1.80 | 4/5 | 55.56% |
| -200 | 1.50 | 1/2 | 66.67% |
For positive American odds, decimal = 1 + odds ÷ 100. For negative, decimal = 1 + 100 ÷ the odds without the minus sign. Implied probability is 1 ÷ decimal, and fractional odds are decimal minus 1, written as a fraction.
Frequently asked questions
How do I convert American odds to decimal?
For positive odds, divide by 100 and add 1: +150 is 1 + 1.5 = 2.50. For negative odds, divide 100 by the number without its minus sign and add 1: -200 is 1 + 0.5 = 1.50.
How do I convert decimal odds to American?
At 2.00 or above, subtract 1 and multiply by 100: 2.50 is +150. Below 2.00, divide -100 by the decimal odds minus 1: 1.80 is -100 ÷ 0.80 = -125.
What is implied probability?
The win rate the odds imply, which is also the break-even rate for the bet. It is 1 ÷ decimal odds: +150 (2.50) is 40%, and -200 (1.50) is 66.67%. Add up both sides of a market and the amount over 100% is the book’s margin.
What do fractional odds mean?
Profit per unit staked. 5/2 means you win $5 for every $2 bet, so a $10 bet at 5/2 wins $25 and returns $35 with your stake. Evens (1/1) doubles your money.
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Every BreadSync calculator is free to use without an account, and that is not changing. They work on the odds you type in.
BreadSync Pro shows live odds from 130+ sportsbooks in the format you prefer, with the best price on every side highlighted.
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21+. Worked examples are illustrative and use made-up prices; real odds change constantly. Calculator results are estimates for information only, not betting advice or a guarantee of profit. BreadSync is not a sportsbook and does not accept wagers. If gambling stops being fun, call 1-800-GAMBLER.