American
Decimal
Fraction
Implied Probability
%
What is Odds Converter Calculator?
The Odds Converter Calculator is a versatile tool that allows you to seamlessly convert between different odds formats: American, Decimal, Fractional, and Implied Probability. Understanding different odds formats is crucial for comparing betting lines across various sportsbooks and regions.
This calculator simplifies the conversion process, providing instant results and helping you make informed betting decisions. It also includes clear descriptions of each odds format, aiding both novice and experienced bettors.
How to Use the Odds Converter Calculator
1. Enter the odds you wish to convert in any of the four input fields: American, Decimal, Fraction, or Implied Probability.
2. As you type, the calculator will automatically convert the entered odds into the other three formats.
3. The "Implied Probability" field includes a percentage (%) sign for clarity. For fractional odds, enter them in the format "numerator/denominator" (e.g., "5/2").
4. Click on the input fields to auto-select the entire value.
Example
For example, if you enter American odds of "+150", the calculator will instantly display:
- Decimal: 2.50
- Fraction: 3/2
- Implied Probability: 40.00%
Similarly, entering a decimal odds of 3.00 would convert it to:
- American: 200
- Fraction: 2/1
- Implied Probability: 33.33%
Frequently asked questions
How do American, decimal, and fractional odds relate?
They are three notations for the same payout. Decimal odds show total return per unit staked, American odds quote profit relative to 100 units, and fractional odds quote profit as a fraction of stake. The converter maps any one to the others exactly.
What is implied probability?
It is the win probability at which a price would be exactly break-even: 1 divided by the decimal odds. A 2.50 price implies 40%. If your estimate of the true probability is higher than the implied number, the bet is positive EV.
Why do implied probabilities across a market add up to more than 100%?
Because every price carries the sportsbook margin. The amount over 100% is the vig — strip it with a no-vig calculator to see the fair market prices.
Which format should I use for betting math?
Decimal is the easiest to compute with: EV, parlay multiplication, and Kelly formulas all take decimal odds directly. American odds are a display convention, not a math-friendly one.