Margin / Overround Calculator
Paste the odds for a 2- or 3-way market to see the bookmaker margin. Anything under 4% is sharp; over 8% is poor value.
Enter odds and press Calculate.
How it works
Implied probability of any decimal odds is 1 / odds. In a fair market, all outcomes' implied probabilities sum to 100%. Anything above 100% is the bookmaker's edge:
margin % = (sum of 1/odds − 1) × 100
For comparison: Pinnacle and Betfair Exchange typically run 2–4% on football 1X2; high-street bookies often run 6–10%.