Fractional to Decimal Odds Converter
Instantly convert Fractional odds to Decimal, American, and Implied Probability. Professional betting calculator with profit visualization.
Format: Numerator/Denominator
Total Payout per Unit
Positive or Negative Integer
Profit Simulator
About
This tool provides a professional-grade interface for converting between the three dominant betting odds formats: Fractional (UK/Ireland), Decimal (Europe/Australia/Canada), and American (US Moneyline). Unlike simple lookup tables, this calculator uses precise floating-point logic to determine the Implied Probability and Return on Investment.
Accurate odds conversion is critical for arbitrage betting and risk management. A misunderstanding of odds formats can lead to incorrect stake sizing and significant financial variance. This tool assumes standard bookmaker rules where the stake is returned in the payout for Fractional and Decimal formats.
Formulas
1. Fractional to Decimal
Oddsdec = NumeratorDenominator + 1
Where Numerator represents the potential profit and Denominator represents the stake required.
2. Implied Probability
P = 1Oddsdec × 100%
Reference Data
| Fractional | Decimal | American | Probability |
|---|---|---|---|
| 1/4 | 1.25 | -400 | 80.0% |
| 1/2 | 1.50 | -200 | 66.7% |
| 1/1 (Evens) | 2.00 | +100 | 50.0% |
| 6/5 | 2.20 | +120 | 45.5% |
| 6/4 | 2.50 | +150 | 40.0% |
| 2/1 | 3.00 | +200 | 33.3% |
| 5/2 | 3.50 | +250 | 28.6% |
| 3/1 | 4.00 | +300 | 25.0% |
| 4/1 | 5.00 | +400 | 20.0% |
| 10/1 | 11.00 | +1000 | 9.1% |
| 100/1 | 101.00 | +10000 | 1.0% |