Enter odds in any format — Decimal, Fractional, or American (Moneyline) — and the Odds Converter instantly translates them into all three formats plus the Implied Probability. Just fill in one field and the rest update automatically. Useful for comparing lines across sportsbooks that display odds differently.
Implied Probability
--
Decimal Odds
--
Fractional Odds
--
American (Moneyline) Odds
--
For decimal odds of 2.00 or higher (underdog), the formula is: American = (Decimal − 1) × 100. For decimal odds below 2.00 (favourite), the formula is: American = −100 ÷ (Decimal − 1). For example, decimal 2.50 converts to +150, and decimal 1.50 converts to −200.
Divide the numerator by the denominator and add 1. For example, 3/2 becomes (3 ÷ 2) + 1 = 2.50 in decimal format. Fractional odds of 1/1 (evens) equal decimal 2.00.
For positive American odds (e.g. +150): Decimal = (American ÷ 100) + 1. For negative American odds (e.g. −200): Decimal = (100 ÷ |American|) + 1. So +150 = 2.50 decimal, and −200 = 1.50 decimal.
First convert fractional to decimal by dividing numerator by denominator and adding 1. Then apply the decimal-to-American formula. Alternatively: if fraction > 1, American = (numerator ÷ denominator) × 100. If fraction < 1, American = −(denominator ÷ numerator) × 100.
Implied probability tells you the bookmaker's estimated chance of an outcome occurring. From decimal odds: Probability = 1 ÷ Decimal × 100. From American positive odds: Probability = 100 ÷ (American + 100) × 100. From American negative odds: Probability = |American| ÷ (|American| + 100) × 100.
From probability (as a decimal between 0 and 1): Decimal odds = 1 ÷ probability. American odds = (1 ÷ probability − 1) × 100 for underdogs, or −probability ÷ (1 − probability) × 100 for favourites. Fractional odds = (1 − probability) ÷ probability, then simplify.
Decimal odds (e.g. 2.50) represent the total return per unit staked including stake. Fractional odds (e.g. 3/2) show profit relative to stake. American odds use +/− values where positive shows profit on a $100 bet and negative shows how much you must stake to win $100. All formats convey the same underlying probability — they're just different representations.
Implied probability lets you compare the bookmaker's estimated chance of an outcome against your own assessment. If you believe an outcome has a higher probability than the implied probability suggests, you've found a value bet. It also helps you identify when the bookmaker's margin (vig or juice) is eating into your returns, since all implied probabilities across a market will typically sum to more than 100%.