This calculator helps you determine the built-in margin within bookmaker odds, as well as the fair odds (also known as true odds) without the margin. We offer separate tools for 2-way, 3-way, and 4-way markets, so you can choose the right calculator based on your betting scenario and make more informed decisions.
Fair Odds Calculator
How to Use the Fair Odds Calculator
- Select 2way, 3way or 4way tab
- Enter each odds value
- Check Results
What are the Fair odds?
In sports betting, Fair Odds (also known as true odds) represent the real probability of an event happening—without the bookmaker’s margin. Bookmakers include a built-in edge in their odds to ensure profit, meaning the odds you see are often lower than the actual probabilities. By calculating fair odds, you can better assess whether a bet has value and make more informed betting decisions.
Understanding the Bookmaker’s Margin
Bookmaker odds are rarely a pure reflection of probability. In fact, the total implied probability of all outcomes in a market typically exceeds 100% due to the built-in margin.
For example, imagine a soccer match where the odds are:
Home win: 2.30
Draw: 3.50
Away win: 3.10
To find the margin, convert each to implied probability:
1 / 2.30 = 0.4348
1 / 3.50 = 0.2857
1 / 3.10 = 0.3226
Total = 1.0431 or 104.13%
The extra 4.13% is the bookmaker’s margin. When you remove that margin, you get the fair odds—the odds that reflect the true probability.
Why Fair Odds Matter in Sports Betting
Fair odds help you identify whether a bookmaker’s offering is worth betting on. They let you evaluate whether you're getting enough return relative to the risk. Understanding fair odds is essential for developing a successful sports betting strategy.
How to Use Fair Odds to Win More Bets
1. Find Value Bets
If a bookmaker offers odds that are higher than the fair odds, you’ve found a value bet. For example, if the fair odds suggest 2.10, but a bookmaker offers 2.30, the odds are better than they should be—offering positive expected value. Repeatedly betting on value increases your chance of long-term profit.
2. Spot Arbitrage Opportunities
By comparing odds across multiple bookmakers, you can sometimes find a situation where betting on all outcomes results in a guaranteed profit—known as arbitrage betting. Fair odds calculations help detect these rare but lucrative opportunities.
Conclusion
Understanding and calculating fair odds is a powerful skill for anyone serious about sports betting. By removing the bookmaker’s margin and evaluating the real probabilities, you can identify value bets and improve your long-term results. Use Our Fair Odds Calculator to sharpen your strategy and make smarter bets.
