📊 Implied Probability Calculator

Convert betting odds to implied probability and understand the bookmaker's edge

All Formats Odds Types
Overround Analysis
True % Probability
Moneky tilt head

Implied Probability Calculator

Single Odds Conversion

Market Overround Calculator

Calculate the bookmaker's margin and true probabilities for any betting market

Understanding Implied Probability

Implied probability is the likelihood of an outcome according to betting odds, expressed as a percentage. It includes the bookmaker's margin (overround) built into the odds.

Implied Probability Formula

Implied Probability = (1 ÷ Decimal Odds) × 100
For American odds: Convert to decimal first, then apply formula

📊 Probability Examples

Even Money (2.00 decimal): 50% probability
Heavy Favorite (1.20 decimal): 83.33% probability
Long Shot (10.00 decimal): 10% probability
American +150 (2.50 decimal): 40% probability

⚠️ Key Insight

Implied probability includes the bookmaker's profit margin. The sum of all outcomes in a market typically exceeds 100%, with the excess being the overround.

Overround and True Probability

The overround (or vigorish) is the bookmaker's built-in profit margin. Understanding it helps you find value bets and calculate true probabilities.

🧮 Overround Calculation Example

Two-way market example:
• Team A: 1.91 odds = 52.36% implied probability
• Team B: 1.91 odds = 52.36% implied probability
• Total: 52.36% + 52.36% = 104.72%
• Overround: 104.72% - 100% = 4.72%
• Bookmaker margin: 4.72% ÷ 104.72% = 4.51%
✅ The 4.51% is the bookmaker's profit margin on this market

📈 True Probability

True Probability = (Implied Probability ÷ Total Market Probability) × 100

This removes the bookmaker's margin to show the actual likelihood of each outcome.

💡 Finding Value

Compare true probabilities to your own estimates. If you think an outcome has higher probability than the true probability suggests, it may be a value bet.

Probability-Based Betting Strategy

✅ Best Practices

  • Always calculate implied probabilities before betting
  • Look for markets with lower overround (better value)
  • Compare your probability estimates to true probabilities
  • Understand the bookmaker's margin on each market
  • Use probability analysis for bankroll management

⚠️ Common Mistakes

  • Ignoring bookmaker margins in probability analysis
  • Betting without calculating implied probabilities
  • Not comparing across different bookmakers
  • Overestimating your own probability estimates
  • Focusing only on odds without understanding probability

Pros and Cons of Probability Analysis

✅ Pros

  • Reveals bookmaker margins and true value
  • Helps identify profitable betting opportunities
  • Enables data-driven betting decisions
  • Works across all sports and bet types
  • Essential for professional betting strategies

❌ Cons

  • Requires accurate probability estimation skills
  • Market analysis can be time-intensive
  • Overconfidence in probability estimates is risky
  • Bookmaker margins vary significantly by market
  • Probability doesn't guarantee outcomes

Frequently Asked Questions