Betting Odds Explained
Betting odds tell you two things: how likely the bookmaker thinks an outcome is, and how much you stand to win. There are three main formats — fractional, decimal, and American. All three convey the same information, just expressed differently.
Fractional Odds
The traditional UK format. The first number (numerator) is your profit; the second (denominator) is the stake required. Formula: profit = stake × (numerator ÷ denominator)
| Odds | £10 stake | Profit | Total Return |
|---|---|---|---|
| 1/1 (Evens) | £10 | £10.00 | £20.00 |
| 2/1 | £10 | £20.00 | £30.00 |
| 5/2 | £10 | £25.00 | £35.00 |
| 1/2 | £10 | £5.00 | £15.00 |
| 7/4 | £10 | £17.50 | £27.50 |
Decimal Odds
The European standard — and the easiest format to calculate with. Decimal odds represent your total return (including stake) per unit staked. Formula: total return = stake × decimal odds; profit = return − stake
| Odds | £10 stake | Total Return | Profit |
|---|---|---|---|
| 1.50 | £10 | £15.00 | £5.00 |
| 2.00 | £10 | £20.00 | £10.00 |
| 3.00 | £10 | £30.00 | £20.00 |
| 5.00 | £10 | £50.00 | £40.00 |
| 10.00 | £10 | £100.00 | £90.00 |
American (Moneyline) Odds
Used primarily in the USA. There are two cases:
- Positive (+200): profit per £100 staked. Profit = stake × (X ÷ 100)
- Negative (−150): stake needed to profit £100. Profit = stake × (100 ÷ Y)
| Odds | £10 stake | Profit | Total Return |
|---|---|---|---|
| +100 | £10 | £10.00 | £20.00 |
| +200 | £10 | £20.00 | £30.00 |
| +500 | £10 | £50.00 | £60.00 |
| −150 | £10 | £6.67 | £16.67 |
| −200 | £10 | £5.00 | £15.00 |
Converting Between Formats
| Fractional | Decimal | American | Implied Prob. |
|---|---|---|---|
| 1/2 | 1.50 | −200 | 66.67% |
| Evens (1/1) | 2.00 | +100 | 50.00% |
| 6/4 | 2.50 | +150 | 40.00% |
| 7/4 | 2.75 | +175 | 36.36% |
| 2/1 | 3.00 | +200 | 33.33% |
| 5/2 | 3.50 | +250 | 28.57% |
| 4/1 | 5.00 | +400 | 20.00% |
| 9/1 | 10.00 | +900 | 10.00% |
Which Format Should I Use?
- UK & Ireland — fractional is the traditional format, still widely used by UK bookmakers
- Europe & Australia — decimal is the standard; easier for multi-bet maths
- USA — American (moneyline) is universal; all major US sportsbooks use it
Convert odds instantly
Use our free odds converter for any format.