Odds Converter
Type odds in any format, or a chance as a percentage, and see them in all three styles with the probability the price suggests.
Betting is for adults aged 18 or over, and you can lose money. This page explains the maths and does not encourage betting. If gambling is a problem for you or someone close to you, contact BeGambleAware or GamCare (National Gambling Helpline 0808 8020 133).
Worked examples
A fractional price
5/2
3.5 decimal, +250 American, 28.6% implied chance
A £10 stake returns £35 if it wins, a profit of £25.
An American price
-110
1.91 decimal, 10/11 fractional, 52.4% implied chance
The usual price on each side of an American point spread.
About Odds Converter
An odds converter changes a price from one betting style to another. Bookmakers in the UK usually show fractional odds such as 5/2, exchanges and many European sites use decimal odds such as 3.5, and American sportsbooks use money line odds such as +250 or -200. The numbers look different but describe the same bet, and this page lets you type any one of them to see the other two.
Every price also says something about chance. Decimal odds of 4.0 mean the bookmaker rates an outcome at 1 in 4, or 25%. The converter shows that implied chance next to the prices, and a table of what a stake would return. The chance includes the bookmaker's margin, so the true chance is a little lower. This page explains the maths and does not encourage betting.
How to use Odds Converter
- Choose whether you are starting from odds or from a chance in per cent.
- Type the odds, such as 5/2, 3.5 or +250. Leave the format on detect, or pick one if the number is ambiguous.
- Read the fractional, decimal and American versions and the implied chance.
- Enter a stake to see the profit and the total returned if the bet wins.
Common uses
- Comparing a UK bookmaker with an American sportsbook
- Checking what a price implies before reading an article about a market
- Turning a forecast chance into the odds it would be worth
- Learning how the three styles relate
Frequently asked questions
How do I convert fractional odds to decimal?
Divide the top number by the bottom number and add 1. So 5/2 is 2.5 plus 1, which is 3.5. The decimal figure is the total return for each pound staked, including the stake.
What do American odds like +250 and -200 mean?
A plus figure is the profit on a stake of 100, so +250 wins 250 on 100 and is 3.5 in decimal. A minus figure is the stake needed to win 100, so -200 means staking 200 to win 100, which is 1.5 in decimal.
How is the implied chance worked out?
It is 1 divided by the decimal odds. Odds of 3.5 give 1 divided by 3.5, which is 28.6%. Evens, or 2.0, gives 50%.
Why does 1.91 show as 10/11?
Bookmakers use a set of familiar fractions. The page finds the simplest one that matches the decimal price to within half a penny, and 10/11 gives 1.909, which rounds to 1.91.
Is the implied chance the real chance?
No. The prices on a market include a margin for the bookmaker, so the implied chances add up to more than 100%. The overround calculator shows how much and removes it.