Odds Conversion Calc
Decimal, fractional, American — convert instantly and see the implied chance.
How to Use This Calculator
- Flip the toggle to your preferred odds format (Decimal, Fractional, or American)
- Punch the odds value into the input field
- Watch it spit out the same price across 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
Decimal odds — what are they?
Decimal odds spell out the full return on every $1 you stake, your stake included. So odds of 2.50 hand you back $2.50 for each $1 wagered — that’s $1.50 in profit.
How do American odds work?
American odds run on plus and minus signs. A positive number like +150 tells you the profit on a $100 bet. A negative number like -200 tells you how much you must stake to clear $100 in profit.
And fractional odds?
Fractional odds such as 3/2 mean you collect $3 in profit for every $2 you put down. The first figure is your winnings, the second is the stake.
What does implied probability mean?
Implied probability turns odds into a percentage, revealing how likely the bookmaker reckons the outcome is. The shorter the odds, the higher that probability climbs.