Odds & Probability Converter
Convert between American, decimal, and fractional odds and see the implied probability and break-even win rate for any price. Use this tool to better understand what the odds at your sportsbook really mean.
Knowing your required win rate makes it easier to think about long-term betting success rather than short-term results. Enter any odds format and instantly see what they mean across every standard.
Formats
American, decimal, fractional
Outputs
All formats plus implied probability
Use case
Learn what you must win long-term to break even
This tool is for education and entertainment only. It does not place bets or guarantee outcomes. Always check final odds directly in your sportsbook app before wagering.
How to Use This Odds Tool
Whether you're comparing lines across sportsbooks or trying to understand what your odds actually mean, this converter does the math for you in real time.
Choose the odds format you have
Select whether you're entering American, decimal, or fractional odds. Most US sportsbooks default to American odds, but you may encounter decimal odds on international books or fractional odds on UK-based platforms.
Enter the odds value
Type the odds exactly as they appear on your sportsbook. For American odds, include the sign (e.g. "-110" or "+250"). For decimal odds, enter a number greater than 1 (e.g. "1.91" or "2.50"). For fractional odds, use a slash (e.g. "5/2" or "10/11").
Review the converted formats
Once you enter valid odds, the converter instantly displays the equivalent in all three formats — American, decimal, and fractional — so you can compare across sportsbooks regardless of how they display their lines.
Understand implied probability and break even
The tool also shows two key numbers: implied probability (the win rate suggested by the odds) and break even win rate (the percentage of wins you need at those odds to break even long-term). For example, -110 American odds correspond to decimal odds of about 1.91 and an implied probability near 52.4%.
Frequently Asked Questions
What is implied probability in sports betting?
Implied probability is the win percentage suggested by a set of odds. It tells you how often a bet at those odds would need to win to break even over time. It helps bettors think in terms of value and long-term results rather than just individual outcomes.
What is the difference between American, decimal, and fractional odds?
American odds use plus/minus numbers relative to $100 — a minus number shows how much you must risk to win $100, and a plus number shows how much you win on a $100 bet. Decimal odds show the total return per unit staked (including your original bet). Fractional odds express profit relative to stake (e.g. 5/2 means $5 profit for every $2 wagered).
Why does the break even win rate matter?
The break even win rate tells you the minimum percentage of the time your bet must win to avoid losing money at those odds over a large sample. If you believe a team wins more often than the break even percentage, the bet has positive expected value.
Does this converter include the sportsbook vig or edge?
The converter reflects whatever vig exists in the odds you enter. It doesn't attempt to strip out or calculate fair no-vig prices — it simply converts the odds as displayed and shows the implied probability they carry.
Can I use this for live betting odds?
Yes. The converter works with any valid odds value, whether it comes from a pre-game line or a live in-play market. Just enter the current odds and the tool will convert them in real time.
Why does the fractional odds output sometimes look unusual?
The converter approximates and simplifies fractions to be as readable as possible. For common odds like -110 or +150, the fractions are clean and familiar. For unusual prices, the output may look less standard but is still mathematically accurate.