Betting Odds Conversion Calculator

Betting Odds Conversion Calculator

Use our Betting Odds Converter to convert betting odds from any odds format (Decimal, Fractional, or American/Moneyline odds) to any other format. The betting odds calculator also calculates the implied probability of your bet, as well as the estimated payout amount depending on the bet amount you enter.

How to Convert Betting Odds

It can be useful to know the formulas for converting betting odds from one format to another, especially if you are traveling to a different country or using a different sportsbook that doesn’t display betting odds in the format you are most familiar with. Knowing how to calculate the implied probability (the percentage chance of your bet winning) will help you to make more informed betting decisions.

Convert Decimal Odds to Fractional Odds

To convert decimal odds to fractional odds, subtract 1 from the decimal odds. E.g. Decimal odds of 6.00 converted to fractional odds is 6.00 - 1 = 5/1

Convert Decimal Odds to American Odds

When the decimal odds are 2.00 or higher, the formula is (decimal odds - 1) * 100. E.g. Decimal odds of 2.50 converted to American odds is (2.50 - 1) x 100 = 150.

When the decimal odds are between 1.01 and 1.99, the conversion formula is: -100 / (decimal odds - 1). E.g. Decimal odds of 1.50 converted to American odds is -100 / (1.50 - 1) = -200.

Convert Fractional Odds to Decimal Odds

Divide the top fraction number by the bottom number and add 1.00. E.g. fractional odds 1/4 displayed as decimal odds is 1 / 4 = 0.25 + 1 = 1.25.

Convert Fractional Odds to American Odds

When the Fractional odds are greater than 1, the conversion formula is (fractional value) * 100. E.g. fractional odds of 2/1 converted to American odds is (2 / 1) x 100 = 200.

When the Fractional odds are less than 1, the conversion formula is -100 / (fractional value). E.g. Fractional odds of 1/3 converted to American odds is -100 / (1/3) = -300.

Convert American Odds to Decimal Odds

To convert American (moneyline) odds to Decimal odds, a different calculation is used depending if the American odds is a negative number or a positive number. When the American odds is a positive number, divide it by 100 and add 1.00. E.g. American odds of 400 converted to decimal odds is (400 / 100) + 1 = 5.00.

When the American odds are negative, divide 100 by the odds (without the minus sign) and add 1.00. E.g. money line odds of -300 converted to decimal odds is (100 / 300) + 1 = 1.3

Convert American Odds to Fractional Odds

When the American odds is a positive number, the conversion formula is: American odds / 100. E.g. American odds of +300 converted to Fractional odds is 300 / 100 = 3/1.

When the American odds is a negative number, the conversion formula is: -100 / - American odds. E.g. American odds of -400 converted to Fractional odds is -100 / -400 = 1/4.

How to Calculate Implied Probability of Winning a Bet

The implied probability is the chance of your bet winning, displayed as a simple percentage. 

To convert Decimal odds to implied probability, use the following formula: (1 / decimal odds) x 100. For example, betting odds of 1.2 converted to implied probability is (1 / 1.2) x 100 = 83.33%.