Free Odds Converter

Convert between American, decimal, and fractional odds instantly. See the implied probability for any odds format.

American Oddse.g., -110 or +200

Decimal Oddse.g., 1.91 or 3.00

Fractional Oddse.g., 10/11 or 2/1

Enter odds in any format above to see instant conversions and implied probability.

Understanding Betting Odds Formats

American Odds (Moneyline)

American odds use a +/- system based on $100. Positive odds (e.g. +150) show your profit on a $100 bet. Negative odds (e.g. -110) show how much you need to bet to win $100.

Decimal Odds

Decimal odds represent your total return per unit wagered, including your stake. Odds of 2.50 mean you receive $2.50 for every $1 bet (profit of $1.50). Decimal odds are common in Europe and Australia.

Fractional Odds

Fractional odds (e.g. 3/1) show profit relative to stake. A 3/1 bet wins $3 for every $1 wagered. These are popular in UK horse racing and traditional betting markets.

Quick Conversion Reference

American	Decimal	Fractional	Implied Prob.
-500	1.20	1/5	83.3%
-200	1.50	1/2	66.7%
-150	1.67	2/3	60.0%
-110	1.91	10/11	52.4%
+100	2.00	1/1	50.0%
+150	2.50	3/2	40.0%
+200	3.00	2/1	33.3%
+300	4.00	3/1	25.0%
+500	6.00	5/1	16.7%
+1000	11.00	10/1	9.1%

Odds Converter FAQ

What are American odds?

American odds (also called moneyline odds) use positive and negative numbers. Positive odds like +200 mean you win $200 profit on a $100 bet. Negative odds like -150 mean you must bet $150 to win $100 profit. They're the standard format at US sportsbooks.

How do I convert American odds to decimal?

For positive odds: divide by 100 and add 1. Example: +200 = (200/100) + 1 = 3.00. For negative odds: divide 100 by the absolute value and add 1. Example: -150 = (100/150) + 1 = 1.667.

What is implied probability?

Implied probability is the chance of winning implied by the odds. For +200 odds: 100 / (200 + 100) = 33.3%. For -150 odds: 150 / (150 + 100) = 60%. When your estimated probability exceeds the implied probability, that's a positive expected value bet.

What's the difference between decimal and fractional odds?

Decimal odds include your stake in the return (2.50 means you get $2.50 back per $1 wagered, $1.50 profit). Fractional odds show profit only (3/2 means $1.50 profit per $1 staked). Decimal odds are easier for probability calculations.