Probability calculator
Calculate intersections, unions, complements and conditional probabilities for two events.
Enter probabilities from 0 to 100%. The supplied intersection must satisfy the Fréchet bounds. Independence is used only when explicitly selected. Conditional probabilities with a zero denominator are undefined, not zero. Change the input or settings to update your result. Results update as you type. Up to 1,000,000 characters.
Your result
How to use Probability calculator
- Enter the observations or summary values.
- Choose the method and check its assumptions.
- Review the result and download the calculation.
Useful next steps
Choose the model before reading the result
Calculate intersections, unions, complements and conditional probabilities for two events.
Check the assumptions
Enter probabilities from 0 to 100%. The supplied intersection must satisfy the Fréchet bounds. Independence is used only when explicitly selected. Conditional probabilities with a zero denominator are undefined, not zero.
Keep the calculation
Download the JSON for unrounded results and settings, CSV for the table, and the separate assumptions note. The calculation runs in your browser.