Decimal | Fractional | American | Probability |
---|---|---|---|

1 | 0/∞ | -∞ | 100% |

1.01 | 1/100 | -10000 | 99.01% |

1.02 | 1/50 | -5000 | 98.04% |

1.03 | 1/33 | -3333 | 97.09% |

1.04 | 1/25 | -2500 | 96.15% |

1.05 | 1/20 | -2000 | 95.24% |

1.06 | 1/16 | -1667 | 94.34% |

1.07 | 1/14 | -1429 | 93.46% |

1.08 | 1/13 | -1250 | 92.59% |

1.09 | 1/11 | -1111 | 91.74% |

1.1 | 1/10 | -1000 | 90.91% |

1.11 | 1/9 | -909 | 90.09% |

1.12 | 2/17 | -833 | 89.29% |

1.13 | 2/15 | -769 | 88.5% |

1.14 | 1/7 | -714 | 87.72% |

1.15 | 2/13 | -667 | 86.96% |

1.16 | 2/13 | -625 | 86.21% |

1.17 | 1/6 | -588 | 85.47% |

1.18 | 2/11 | -556 | 84.75% |

1.19 | 2/11 | -526 | 84.03% |

1.2 | 1/5 | -500 | 83.33% |

1.22 | 2/9 | -455 | 81.97% |

1.25 | 1/4 | -400 | 80% |

1.28 | 2/7 | -357 | 78.13% |

1.3 | 3/10 | -333 | 76.92% |

1.33 | 1/3 | -303 | 75.19% |

1.35 | 7/20 | -286 | 74.07% |

1.36 | 4/11 | -278 | 73.53% |

1.4 | 2/5 | -250 | 71.43% |

1.44 | 4/9 | -227 | 69.44% |

1.45 | 9/20 | -222 | 68.97% |

1.47 | 8/17 | -213 | 68.03% |

1.5 | 1/2 | -200 | 66.67% |

1.53 | 8/15 | -189 | 65.36% |

1.57 | 4/7 | -175 | 63.69% |

1.6 | 3/5 | -167 | 62.5% |

1.62 | 8/13 | -161 | 61.73% |

1.63 | 5/8 | -159 | 61.35% |

1.66 | 2/3 | -152 | 60.24% |

1.7 | 7/10 | -143 | 58.82% |

1.72 | 8/11 | -139 | 58.14% |

1.8 | 4/5 | -125 | 55.56% |

1.83 | 5/6 | -120 | 54.54% |

1.9 | 9/10 | -111 | 52.63% |

1.91 | 10/11 | -110 | 52.36% |

1.95 | 20/21 | -105 | 51.28% |

2 | 1/1 | +/-100 | 50% |

2.05 | 21/20 | +105 | 48.78% |

2.1 | 11/10 | +110 | 47.62% |

2.2 | 6/5 | +120 | 45.45% |

2.25 | 5/4 | +125 | 44.44% |

2.3 | 13/10 | +130 | 43.48% |

2.38 | 11/8 | +138 | 42.02% |

2.4 | 7/5 | +140 | 41.67% |

2.5 | 3/2 | +150 | 40% |

2.6 | 8/5 | +160 | 38.46% |

2.63 | 13/8 | +163 | 38.02% |

2.7 | 17/10 | +170 | 37.04% |

2.75 | 7/4 | +175 | 36.36% |

2.8 | 9/5 | +180 | 35.71% |

2.88 | 15/8 | +188 | 34.72% |

2.9 | 19/10 | +190 | 34.48% |

3 | 2/1 | +200 | 33.33% |

3.1 | 21/10 | +210 | 32.26% |

3.13 | 17/8 | +213 | 31.95% |

3.2 | 11/5 | +220 | 31.25% |

3.25 | 9/4 | +225 | 30.77% |

3.3 | 23/10 | +230 | 30.3% |

3.38 | 19/8 | +238 | 29.59% |

3.4 | 12/5 | +240 | 29.41% |

3.5 | 5/2 | +250 | 28.57% |

3.6 | 13/5 | +260 | 27.78% |

3.75 | 11/4 | +275 | 26.67% |

3.8 | 14/5 | +280 | 26.32% |

4 | 3/1 | +300 | 25% |

4.2 | 16/5 | +320 | 23.81% |

4.33 | 10/3 | +333 | 23.09% |

4.5 | 7/2 | +350 | 22.22% |

4.6 | 18/5 | +360 | 21.74% |

5 | 4/1 | +400 | 20% |

5.5 | 9/2 | +450 | 18.18% |

6 | 5/1 | +500 | 16.67% |

6.5 | 11/2 | +550 | 15.38% |

7 | 6/1 | +600 | 14.29% |

7.5 | 13/2 | +650 | 13.33% |

8 | 7/1 | +700 | 12.5% |

8.5 | 15/2 | +750 | 11.76% |

9 | 8/1 | +800 | 11.11% |

9.5 | 17/2 | +850 | 10.53% |

10 | 9/1 | +900 | 10% |

11 | 10/1 | +1000 | 9.09% |

20 | 19/1 | +1900 | 5% |

30 | 30/1 | +2900 | 3.33% |

40 | 40/1 | +3900 | 2.5% |

50 | 50/1 | +4900 | 2% |

60 | 60/1 | +5900 | 1.67% |

70 | 70/1 | +6900 | 1.43% |

80 | 80/1 | +7900 | 1.25% |

90 | 90/1 | +8900 | 1.11% |

100 | 100/1 | +9900 | 1% |

1000 | 1000/1 | +99900 | 0.1% |

Converting odds between different formats and calculating implied probability from odds are important skills in the world of betting and gambling.

The three main types of odds are **American, Decimal & Fractional odds**. Each format represents the same probability but expressed in a different way.

Let’s go through the formulas required to convert between these formats and to calculate the implied probability.

## 1. American Odds

American sports-betting odds are either positive or negative numbers.

### Conversion Formulas:

#### Convert Odds From Decimal to American:

- If Decimal odds are greater than 2.00: American Odds = (Decimal Odds – 1) * 100
- If Decimal odds are less than 2.00: American Odds = -100 / (Decimal Odds – 1)

#### Convert Odds From Fractional to American:

- If Fractional odds are greater than 1: American Odds = Numerator * (100 / Denominator)
- If Fractional odds are less than 1: American Odds = -Denominator * (100 / Numerator)

### Calculating Implied Probability with American Odds:

- If American odds are positive: Implied Probability = 100 / (American Odds + 100) * 100%
- If American odds are negative: Implied Probability = -American Odds / (-American Odds + 100) * 100%

## 2. Decimal Odds

Decimal odds are straightforward, representing the amount one wins for every $1 wagered.

### Conversion Formulas:

#### Convert Odds From Fractional to Decimal

Decimal Odds = (Numerator / Denominator) + 1. In fractional odds, such as 5/1 or 1/5, the first number (5 in 5/1) is the numerator, and the second number (1 in 5/1) is the denominator. This format essentially represents the potential profit relative to the stake. For instance, 5/1 means you would win 5 units for every 1 unit staked.

#### Convert Odds From American to Decimal:

If American odds are positive: Decimal Odds = (American Odds / 100) + 1

If American odds are negative: Decimal Odds = 1 – (100 / American Odds)

### Calculating Implied Probability with Decimal Odds:

Implied Probability = (1 / Decimal Odds) * 100%

## 3. Fractional Odds

Fractional odds are commonly used in the UK and Ireland.

### Conversion Formulas:

From Decimal to Fractional:

Fractional Odds = (Decimal Odds – 1) / 1 (then simplify the fraction)

#### From American to Fractional:

- If American odds are positive: Fractional Odds = American Odds / 100 (then simplify the fraction)
- If American odds are negative: Fractional Odds = 100 / -American Odds (then simplify the fraction)

**Calculating Implied Probability with Fractional Odds:**

Implied Probability = Denominator / (Numerator + Denominator) * 100%

## Webmasters: Odds Calculator Plugin for WordPress

If you use the WordPress CMS, you can install our easy-to-use *WordPress betting odds calculator plugin* on your domain and embed an odds calculator / converter in your posts/pages or page templates via a simple short-code.

View the info page: Odds Calculator / Converter Plugin for WordPress.