Odds Conversion Sports Calculator
Swap decimal, fractional and American odds and see the chance behind them.
How to Use This Calculator
- Tap the toggle to pick your odds format (Decimal, Fractional, or American)
- Type the odds into the input box
- Instantly see the same odds in all three formats, plus the implied probability
Examples:
- Decimal: 2.50
- Fractional: 3/2
- American: +150 or -200
Formula
Decimal to Fractional: Fractional = Decimal - 1 (expressed as a fraction)
Decimal to American:
- If Decimal >= 2.00: American = (Decimal - 1) x 100
- If Decimal < 2.00: American = -100 / (Decimal - 1)
Implied Probability: 1 / Decimal Odds x 100%
Frequently Asked Questions
How do decimal odds work?
Decimal odds show your total return for every $1 you stake, including the stake itself. So odds of 2.50 mean you get back $2.50 for each $1 you bet, which is $1.50 in profit.
How do American odds work?
American odds come with a + or - sign. A plus number like +150 shows the profit on a $100 bet, while a minus number like -200 shows how much you’d need to stake to make $100 profit.
How do fractional odds work?
With fractional odds like 3/2, you win $3 for every $2 you put down. The first number is your profit and the second is the amount you stake.
What does implied probability mean?
Implied probability turns odds into a percentage that reflects how likely the bookmaker rates an outcome. The shorter the odds, the higher that probability.