Odds Converter
Instantly convert between American, decimal, fractional odds and implied probability. Enter any format and see all conversions in real time.
How Odds Conversion Works
Odds represent the same information in different formats depending on your region. American odds are standard in the US, decimal odds in Europe and Australia, and fractional odds in the UK. Understanding all formats helps you compare lines across international sportsbooks.
American to Decimal
Positive American: (odds / 100) + 1. Negative American: (100 / |odds|) + 1. Example: -110 = (100/110) + 1 = 1.909.
Decimal to Implied Probability
Simply calculate 1 / decimal odds. At 1.909 decimal, the implied probability is 1/1.909 = 52.38%. This includes the vig baked into the sportsbook's odds.
Frequently Asked Questions
How do I convert American odds to decimal?
For positive American odds: divide by 100 and add 1. Example: +200 = (200/100) + 1 = 3.00 decimal. For negative American odds: divide 100 by the absolute value and add 1. Example: -150 = (100/150) + 1 = 1.667 decimal.
What are implied probabilities?
Implied probability is the likelihood of an outcome suggested by the odds. It is calculated as 1 divided by the decimal odds. For example, decimal odds of 2.00 imply a 50% probability. Note that implied probabilities from a sportsbook include the vig, so both sides will sum to more than 100%.
What is the difference between American and decimal odds?
American odds show how much you win on a $100 bet (positive) or how much you need to bet to win $100 (negative). Decimal odds represent the total return per $1 wagered, including your stake. Decimal odds are more straightforward for calculating payouts: simply multiply your stake by the decimal odds.
How do fractional odds work?
Fractional odds (e.g., 5/2) show profit relative to stake. At 5/2, you win $5 for every $2 staked. To convert to decimal: divide the fraction and add 1. So 5/2 = 2.5 + 1 = 3.50 decimal. Fractional odds are most common in UK and European horse racing.
Why do implied probabilities add up to more than 100%?
When you convert both sides of a market to implied probabilities, they sum to more than 100%. This excess is the overround (vig/juice) - the sportsbook's margin. For example, -110 on both sides gives 52.38% + 52.38% = 104.76%, meaning the book has a 4.76% edge.