Bookmaker Margin Calculator
Calculate the overround and true odds from a bookmaker market
How it works
Enter the odds for all outcomes in a market. The calculator shows the bookmaker margin (overround) and what the true fair odds would be without the margin.
Quick Example
Example: PSL match: Chiefs 2.10, Draw 3.20, Pirates 3.50
Step 1: Convert to probabilities: 1/2.10 + 1/3.20 + 1/3.50 = 47.6% + 31.3% + 28.6% = 107.5%
Step 2: Margin = 107.5% - 100% = 7.5%
A lower margin means better value for bettors. Top SA bookmakers typically run 4-8% margins on PSL fixtures.
Check the accepted bet
These figures describe the entered values, not a forecast. Settlement rules, deductions and accepted prices can change the final return.