Enter fractional odds (e.g. 11/10) and your bet amount to instantly see the implied probability, decimal odds, American odds, potential profit, and total payout. The calculator also converts in reverse — enter decimal or American odds and the fractional equivalent updates automatically.
Implied Probability
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Decimal Odds
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American (Moneyline) Odds
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Potential Profit
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Total Payout
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To convert fractional odds (e.g. 11/10) to implied probability, use the formula: Probability = Denominator / (Numerator + Denominator) × 100. For 11/10, that's 10 / (11 + 10) × 100 = 47.62%. This tells you the bookmaker's implied chance of that outcome occurring.
Decimal odds = (Numerator / Denominator) + 1. For example, 11/10 becomes (11 / 10) + 1 = 2.10. Decimal odds include your stake in the return, making them straightforward to use when calculating total payout.
If fractional odds are greater than 1/1 (i.e. the numerator is larger than the denominator), American odds = (Numerator / Denominator) × 100. If fractional odds are less than 1/1, American odds = −(Denominator / Numerator) × 100. For 11/10: (11/10) × 100 = +110.
Fractional odds represent the ratio of profit to stake. Odds of 5/1 mean you win $5 for every $1 wagered (plus your stake back). They are the traditional format used by UK and Irish bookmakers and are common in horse racing markets.
Potential profit = (Numerator / Denominator) × Stake. Total payout = Profit + Stake. For example, a $100 bet at 11/10 returns a profit of $110, and a total payout of $210.
Fractional odds show your profit relative to your stake (e.g. 11/10 means win $11 for every $10 bet). Decimal odds represent the total return per unit staked including the original bet (e.g. 2.10 means get back $2.10 for every $1 bet). Decimal odds are generally easier to calculate payouts with.
To go from probability to fractional odds, first calculate the decimal odds: Decimal = 1 / (Probability / 100). Then subtract 1 to get the fractional equivalent as a ratio. For example, a 47.62% probability gives decimal odds of 2.10, which converts to 11/10 in fractional form.
Fractional odds are most popular in the United Kingdom and Ireland, especially for horse racing. Most of the rest of the world prefers decimal odds, while American sportsbooks use moneyline (American) odds. Many online betting sites now display all three formats simultaneously.