Probability Calculator

This probability math calculator, helps to find the probability of a given event to happen.

Result

Your result will appear here...

How to use:

  • Single Event: Calculate probability of a single event (P = favorable/total)
  • Multiple Events: Calculate combined probability of two events (AND/OR)
  • Conditional: Calculate conditional probability (P(A|B) or P(B|A))
  • Enter the required values and click "Calculate Probability"
  • Use "Show Example" to load sample values

Formulas:

  • Single Event: P = favorable outcomes / total outcomes
  • AND Probability: P(A and B) = P(A) × P(B)
  • OR Probability: P(A or B) = P(A) + P(B) - P(A and B)
  • Conditional: P(A|B) = P(A and B) / P(B)

Examples:

  • Single: 3 favorable out of 6 → 0.5 (50%)
  • Multiple: P(A)=0.5 AND P(B)=0.5 → 0.25 (25%)
  • Conditional: P(A)=0.3, P(B)=0.4 → P(A|B)=0.75