Odds Converter
Convert between decimal, fractional and American (moneyline) odds instantly. Type into any field and the others update live — with the implied probability and your potential payout worked out for you.
e.g. 2.50
e.g. 3/2 or "evens"
e.g. +150 or −200
Common odds, side by side
| Decimal | Fractional | American | Implied probability |
|---|---|---|---|
| 1.50 | 1/2 | −200 | 66.7% |
| 2.00 | 1/1 (evens) | +100 | 50.0% |
| 2.50 | 3/2 | +150 | 40.0% |
| 3.00 | 2/1 | +200 | 33.3% |
| 5.00 | 4/1 | +400 | 20.0% |
| 11.00 | 10/1 | +1000 | 9.1% |
Reading the three formats
Decimal odds show your total return per unit staked, including your stake back. Odds of 2.50 mean a $10 stake returns $25 ($15 profit). They're the easiest for quick maths, which is why most exchanges and European books use them.
Fractional odds (5/2, "five to two") show profit relative to stake: 5 profit for every 2 staked. They're traditional in the UK and Ireland and common on horse racing.
American odds (also called moneyline) use a baseline of 100. A positive number (+150) is the profit on a 100 stake; a negative number (−200) is how much you must stake to win 100. Favourites carry minus odds, underdogs plus odds.
Whatever the format, the implied probability is the honest read on what the odds are really saying — and comparing it to your own estimate of an outcome's chance is the whole game. Bookmakers add a margin on top, so their numbers always imply a total above 100%.
Odds converter FAQ
How do you convert decimal odds to fractional?
Subtract 1 from the decimal odds, then express the result as a fraction. Decimal 3.50 becomes 2.50, which is 5/2. Decimal 2.00 becomes 1.00, or 1/1 (evens).
How do decimal and American odds relate?
For decimal odds of 2.00 or higher, American odds = (decimal − 1) × 100, shown with a plus sign. Below 2.00, American odds = −100 ÷ (decimal − 1). So 2.50 is +150 and 1.50 is −200.
What is implied probability?
Implied probability is the chance an outcome must have for the odds to be 'fair', calculated as 1 ÷ decimal odds. Odds of 2.00 imply 50%. Real bookmaker odds bake in a margin, so the implied probabilities across all outcomes add up to more than 100% — that overround is the house edge on a bet.
Which odds format is best?
They all describe the same thing. Decimal is the clearest for working out total returns (stake × odds). Fractional is traditional in the UK and Ireland. American (moneyline) is standard in the US. This converter shows all three at once so you never have to guess.