Parlay Probability Calculator

Calculate the probability of winning a parlay bet by multiplying the probabilities of each individual bet within the parlay.

Input Parameters

Enter as decimal (e.g., 1.90 for 90% probability) or fraction (e.g., 3/1 for 25% probability)

Calculation Results

Calculation Formula

Probability of winning the parlay = Product of (1 - individual bet probabilities)

Where:
Probability of winning the parlay = Probability of winning Bet 1 × Probability of winning Bet 2 × ... × Probability of winning Bet N
Individual bet probability = 1 / Odds (implied probability)
Note: This calculator uses the implied probability from the odds you provide.

Parlay Probability

%

Probability of Losing

%

Decimal Odds

American Odds

Parlay Probability Calculator Calculator Usage Guide

Learn how to use the Parlay Probability Calculator and understand the probabilities of winning multi-bet parlays

How to Use the Calculator

  1. Add each bet in your parlay by clicking the "Add Another Bet" button.
  2. For each bet, enter a brief description (optional).
  3. Enter the odds for each bet. You can use either:
    • European decimal format (e.g., 1.90 for a 90% chance or 1/10 probability)
    • American odds format (e.g., +190 for a 90% chance or -10 for a 10% chance)
  4. Click the "Calculate" button to see the overall probability of winning the parlay.
  5. The calculator will also display the probability of losing, equivalent decimal odds, and American odds for the parlay.

Understanding Parlay Probabilities

A parlay is a bet that combines multiple individual bets into one. To win a parlay, you must win every single bet within the parlay. Because of this, parlays have lower probabilities of winning than individual bets, but they offer higher potential payouts.

The calculator works by calculating the implied probability of each individual bet (1 divided by the odds) and then multiplying these probabilities together. The formula is:

Probability of winning parlay = (1 - P₁) × (1 - P₂) × (1 - P₃) × ...

Where P₁, P₂, P₃, ... are the probabilities of winning each individual bet.

For example, if you have a 3-bet parlay with odds of 1.90 (European format) for each bet, the probability of winning the parlay is:

Probability = (1 - 1/1.90) × (1 - 1/1.90) × (1 - 1/1.90) = 0.5263 × 0.5263 × 0.5263 = 0.1441 (14.41%)

Example Scenarios

Scenario 1: Simple 2-Bet Parlay

Game 1: Team A to win at odds of 1.80 (European) or +80 (American)

Game 2: Team B to win at odds of 1.95 (European) or +5 (American)

Calculation: (1 - 1/1.80) × (1 - 1/1.95) = 0.4444 × 0.5132 = 0.2281 (22.81% probability of winning)

Scenario 2: More Complex 3-Bet Parlay

Game 1: Team A to win at odds of 1.70 (European) or +30 (American)

Game 2: Team B to win at odds of 2.10 (European) or -10 (American)

Game 3: Over 7.5 points at odds of 1.85 (European) or +15 (American)

Calculation: (1 - 1/1.70) × (1 - 1/2.10) × (1 - 1/1.85) = 0.4118 × 0.4762 × 0.5405 = 0.1069 (10.69% probability of winning)

Important Considerations

  • The lower the probability of winning each individual bet, the lower the probability of winning the parlay.
  • Parlays offer higher payouts than individual bets, but they are riskier.
  • This calculator uses the implied probability from the odds you provide. Make sure your odds are accurate.
  • The calculator does not account for potential pushes (ties) in point spreads or totals bets.