🧮 Professional Betting Calculators
Essential tools for serious bettors. Calculate optimal stakes, convert odds, find arbitrage opportunities, and track your performance.
📊 Kelly Criterion Calculator
Calculate the mathematically optimal stake based on your edge.
Kelly Formula: f* = (bp - q) / b
Where b = odds - 1, p = win probability, q = 1 - p
🔄 Odds Converter
Convert between decimal, fractional, American, and implied probability.
Fractional:
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American:
-
Implied Probability:
-
Common Odds Reference
| Decimal | Fractional | American | Probability |
|---|---|---|---|
| 1.50 | 1/2 | -200 | 66.7% |
| 2.00 | 1/1 (Evens) | +100 | 50.0% |
| 2.50 | 3/2 | +150 | 40.0% |
| 3.00 | 2/1 | +200 | 33.3% |
| 4.00 | 3/1 | +300 | 25.0% |
| 5.00 | 4/1 | +400 | 20.0% |
⚖️ Arbitrage Calculator
Check if arbitrage opportunity exists and calculate stakes.
📈 ROI & Yield Calculator
Track your betting performance over time.
Performance Benchmarks
| Yield | Interpretation |
|---|---|
| Below 0% | Losing bettor |
| 0-3% | Break-even/marginal profit |
| 3-7% | Good profitable bettor |
| 7-10% | Excellent performance |
| 10%+ | Elite (or small sample size) |
🎯 Expected Value Calculator
Calculate the expected value of a bet.
💡 How to Use These Tools
- Kelly Calculator: Use fractional Kelly (1/4 or 1/2) to reduce variance
- Odds Converter: Asian bookmakers use decimal, US books use American
- Arbitrage: Opportunities are rare and often below 3% profit
- ROI Tracking: Need 500+ bets for meaningful data
- EV Calculator: Only bet when EV is positive
Learn how to apply these calculations in our professional betting strategies guide.