New to this? Read: How do betting odds work? · Fractional odds explained · American odds explained
How to use the odds converter
Type a price into any of the four boxes. Decimal odds such as 3.50, fractional odds such as 5/2 or "evens", American odds such as +250 or -200, or an implied probability such as 28.57 all work. The other three boxes update as you type, and the address bar changes too, so you can copy the link and send someone the exact conversion. Reset puts the worked example back.
Bookmakers in the UK and Ireland traditionally show fractional odds, most of Europe, Australia and Canada use decimal odds, and US sportsbooks use American (moneyline) odds. They are three ways of writing the same price. The implied probability is the chance of the outcome that the price suggests, before you account for the bookmaker's margin.
The formulas
- Fractional to decimal: decimal = (numerator ÷ denominator) + 1. So 5/2 = 2.5 + 1 = 3.50.
- Decimal to fractional: subtract 1 and write the result as a fraction. 3.50 − 1 = 2.5 = 5/2. When no simple fraction fits, we show the nearest common bookmaker fraction.
- American to decimal: for a plus price, decimal = 1 + (American ÷ 100); for a minus price, decimal = 1 + (100 ÷ |American|). So +250 = 3.50 and -200 = 1.50.
- Decimal to American: if decimal is 2.00 or more, American = +(decimal − 1) × 100; below 2.00, American = −100 ÷ (decimal − 1).
- Implied probability: 1 ÷ decimal. 3.50 gives 28.57%; 1.50 gives 66.67%.
Worked example 1: 5/2
A team is priced at 5/2 to win. Five divided by two is 2.5, add one for your returned stake, and the decimal price is 3.50. In American odds that is +250, because a 100 stake wins 250. The implied probability is 1 ÷ 3.50 = 28.57%. A 10 stake returns 35 in total if it wins: 25 profit plus the 10 stake.
Worked example 2: -110
A US sportsbook lists Over 2.5 goals at -110. You must stake 110 to win 100, so the decimal price is 1 + 100 ÷ 110 = 1.91. There is no exact simple fraction, so the converter shows 10/11, the nearest price a UK bookmaker would use. The implied probability is 52.36%. If both Over and Under are -110, the two sides add up to 104.7%, and the extra 4.7% is the bookmaker's margin. Our implied probability calculator works this out for a whole market.
Common mistakes
- Forgetting the stake. Fractional odds show profit only; decimal odds include the stake. 2/1 is 3.00, not 2.00.
- Mixing up signs. -150 is a favourite (decimal 1.67); +150 is an outsider (decimal 2.50).
- Reading the implied probability as the true chance. It includes the bookmaker's margin, so the real chance is usually a little lower. Compare it with our football predictions or use the value bet calculator.
- Typing a percentage into a price box. 40 in the decimal box means odds of 40.00, not 40%.
Odds conversion table
The most common football prices in every format. Implied probabilities are rounded to one decimal place.
| Fractional | Decimal | American | Implied probability |
|---|---|---|---|
| 1/5 | 1.20 | -500 | 83.3% |
| 1/4 | 1.25 | -400 | 80.0% |
| 1/3 | 1.33 | -300 | 75.0% |
| 2/5 | 1.40 | -250 | 71.4% |
| 1/2 | 1.50 | -200 | 66.7% |
| 4/6 | 1.67 | -150 | 60.0% |
| 4/5 | 1.80 | -125 | 55.6% |
| 10/11 | 1.91 | -110 | 52.4% |
| Evens (1/1) | 2.00 | +100 | 50.0% |
| 6/5 | 2.20 | +120 | 45.5% |
| 5/4 | 2.25 | +125 | 44.4% |
| 6/4 | 2.50 | +150 | 40.0% |
| 13/8 | 2.63 | +163 | 38.1% |
| 7/4 | 2.75 | +175 | 36.4% |
| 2/1 | 3.00 | +200 | 33.3% |
| 9/4 | 3.25 | +225 | 30.8% |
| 5/2 | 3.50 | +250 | 28.6% |
| 3/1 | 4.00 | +300 | 25.0% |
| 7/2 | 4.50 | +350 | 22.2% |
| 4/1 | 5.00 | +400 | 20.0% |
| 9/2 | 5.50 | +450 | 18.2% |
| 5/1 | 6.00 | +500 | 16.7% |
| 6/1 | 7.00 | +600 | 14.3% |
| 7/1 | 8.00 | +700 | 12.5% |
| 8/1 | 9.00 | +800 | 11.1% |
| 10/1 | 11.00 | +1000 | 9.1% |
| 12/1 | 13.00 | +1200 | 7.7% |
| 16/1 | 17.00 | +1600 | 5.9% |
| 20/1 | 21.00 | +2000 | 4.8% |
| 25/1 | 26.00 | +2500 | 3.8% |
| 33/1 | 34.00 | +3300 | 2.9% |
| 50/1 | 51.00 | +5000 | 2.0% |
| 100/1 | 101.00 | +10000 | 1.0% |
Related
See how we turn our own probabilities into fair odds on the methodology page, check today's Over 2.5 goals predictions, or work out a multiple with the acca calculator.