| 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.