Betting odds converter
Bookmakers show the same price in different formats depending on the country. This converter changes odds between decimal, fractional and American formats and shows the implied probability next to them.
Converter
Converting changes how a price looks, not what it is worth. Fractions are rounded the way bookmakers round them.
Type the odds in any one format and the others update. Nothing you type is stored or sent anywhere.
The formulas in plain words
- Fractional to decimal: divide the top number by the bottom number, then add 1.
- Decimal to implied probability: divide 1 by the decimal odds.
- Positive American odds (+X) to decimal: divide X by 100, then add 1.
- Negative American odds (-X) to decimal: divide 100 by X, then add 1.
Worked example
The same prices in every format, shown as examples.
| Decimal | Fractional | American | Implied probability |
|---|---|---|---|
| 2.50 | 3/2 | +150 | 40.0% |
| 1.50 | 1/2 | -200 | 66.7% |
| 2.00 | 1/1 | +100 | 50.0% |
Take 3/2. Three divided by two is 1.5, plus 1 gives 2.50. One divided by 2.50 is 0.40, or 40%. In American format a price above 2.00 is shown with a plus sign and one below with a minus sign.
What to keep in mind
Converting a price changes how it looks, not what it is worth. Fractional odds are often rounded by bookmakers, so a converted decimal price may differ slightly from the one a site shows.
Implied probability from a single price includes the bookmaker's margin. Across all outcomes of a market, those probabilities add up to more than 100%. A price is not a forecast and does not point to a winner.
Frequently asked questions
How do I convert fractional odds to decimal?
Divide the first number by the second and add 1. For example, 5/2 is 2.5, plus 1 gives 3.50.
What do + and - mean in American odds?
A plus figure is the profit on a 100 unit stake, for example +150. A minus figure is the stake needed to make 100 units of profit, for example -200.
Why do the implied probabilities of a market add up to more than 100%?
Because each price includes the bookmaker's margin. The amount over 100% is called the overround. See our guide to bookmaker margin.