#100 · Odds Formats & Market Comparison Tool

Fractional to Decimal Odds Converter

Convert a fractional price such as 3/2 into its decimal, American and implied-probability equivalents, then see the return for an optional stake.

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How to use this betting tool

  1. Enter the numerator and denominator shown in the fractional price.
  2. Add a stake to calculate monetary return.
  3. Calculate decimal odds, American odds and implied probability.
  4. Keep the original fraction for reference; it is not rounded before conversion.

What this tool calculates

Fractional odds express net profit relative to stake. Decimal odds include the returned stake, so one is added to the fraction.

Decimal = numerator ÷ denominator + 1. Implied probability = denominator ÷ (numerator + denominator).

Fractional odds of 0/1 represent an even return of stake only at decimal 1.00 and are normally not an open betting price.

Worked example

Fractional odds 3/2 equal decimal 2.50, American +150 and 40% implied probability. A $100 stake returns $250 including $150 profit.

Fractional3/2
Decimal2.50
American+150
Implied probability40%
$100 total return$250

Tips and limitations

  • The denominator must be greater than zero.
  • Total return includes the original stake; net profit does not.
  • Displayed American odds are rounded to the nearest whole number.

FAQ

How do I convert 3/2 fractional odds to decimal?

Divide 3 by 2 and add 1, giving decimal odds of 2.50.

What are 5/1 odds in decimal format?

Five divided by one plus one gives decimal odds of 6.00.

How is implied probability calculated from fractional odds?

Divide the denominator by the sum of numerator and denominator, then multiply by 100%.

Why does decimal return include the stake?

Decimal odds quote total return, whereas fractional odds quote net profit relative to stake.

How are fractional odds converted to American odds?

If the fraction is at least 1, multiply it by 100; if below 1, divide −100 by the fraction.

Equivalent 3/2 price

Fractional3/2
Decimal2.50
American+150
Probability40%

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