Contents
How Bookmaker Margin Works
The
What is Bookmaker Margin?
In a fair market:
- Team A at 2.00 (50%) + Team B at 2.00 (50%) = 100%
But bookmakers offer:
- Team A at 1.91 + Team B at 1.91 = 104.7%
That extra 4.7% is the margin — the bookmaker's cut.
Calculating Margin
Margin = (1/Odds1 + 1/Odds2 + ... + 1/OddsN - 1) × 100%
Two-Way Market (Tennis)
- Player A: 1.85
- Player B: 2.00
Margin = (1/1.85 + 1/2.00 - 1) × 100% = 4.05%
Three-Way Market (Football)
- Home: 2.10
- Draw: 3.40
- Away: 3.50
Margin = (1/2.10 + 1/3.40 + 1/3.50 - 1) × 100% = 5.9%
Use our
Why Margin Matters
Long-Term Cost
With 4% margin and $1,000 monthly turnover:
- Monthly "tax": ~$40
- Yearly: ~$480
Finding Value
Lower margin = closer to true odds = easier to find
Margin by Bookmaker
| Bookmaker | Typical Margin | Best For |
|---|---|---|
| 2-3% | Professionals | |
| 4-6% | All-round | |
| 3-5% | Variety | |
| Average | 5-8% | — |
Margin by Sport/Market
| Market | Typical Margin |
|---|---|
| Top football leagues | 3-5% |
| Tennis Grand Slams | 3-4% |
| Lower leagues | 6-10% |
| Exotic markets | 8-15% |
Beating the Margin
Line Shopping
Compare odds across 5+ bookmakers. Take the best odds every time.
Bet Exchanges
Focus on Low-Margin Markets
Stick to major events where competition drives margins down.
Related Tools
Margin Calculator Odds Converter Implied Probability
Track and compare bookmaker margins over time with the
Conclusion
Margin is the price you pay to bet. Minimize it by shopping for best odds and choosing low-margin bookmakers like
Evgeniy Volkov
Fullstack developer with a background in mathematics. I build the calculators and game-style tools on ToolsGambling with Pixi.js and modern web tech, and every result uses transparent probability formulas you can verify yourself.