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Odds converter and implied probability
Type odds in any format to see all three formats and the implied probability the price represents.
How it works
Odds are a price. American odds show either how much you would win on a $100 wager (a plus number) or how much you must wager to win $100 (a minus number). Decimal odds show the total returned per $1 wagered, including your wager. Fractional odds show profit relative to the wager (5/2 means $5 profit per $2 wagered). Implied probability is the chance the price represents, and it includes the sportsbook's margin, so the two sides of a market add up to more than 100%. See how odds work.
The math
- American to decimal: if odds are positive, decimal = 1 + odds/100; if negative, decimal = 1 + 100/|odds|.
- Decimal to American: if decimal is 2.00 or more, American = (decimal - 1) x 100; otherwise American = -100/(decimal - 1).
- Fractional n/d: decimal = 1 + n/d.
- Implied probability = 1 / decimal.
Worked examples
- -110 = decimal 1.9091 = implied probability 52.38%
- +150 = decimal 2.5000 = implied probability 40.00%
- -200 = decimal 1.5000 = implied probability 66.67%
- +100 = decimal 2.0000 = implied probability 50.00%
- +500 = decimal 6.0000 = implied probability 16.67%
What this calculator does not do: it does not tell you what to bet, whether a bet is good value, or how likely any real game outcome is. It only does arithmetic on the numbers you enter, in your browser; nothing you type is sent or saved.