Probability Calculator - calculatorsee.com


Probability Calculator

Calculate probabilities of independent, dependent, mutually exclusive, and conditional events P(A or B), P(A and B).

Calculator Inputs

Likelihood of A occurring (0 to 1).
Likelihood of B occurring (0 to 1).
Relationship.

Calculated Results

Probability P(A and B)
0.1200 (12.0%)
P(A or B) - Union 0.6800 (68.0%)
P(Neither A nor B) 0.3200 (32.0%)
Odds for Event A 2 to 3 (0.67)
Values calculate live as you adjust inputs.

About Probability Calculator

Computes union, intersection, and complementary probabilities for random events based on Kolmogorov probability axioms.

What is Probability Calculator?

Computes union, intersection, and complementary probabilities for random events based on Kolmogorov probability axioms.

How to Use This Calculator

  1. Enter decimal probability of event A and B (0 to 1).
  2. Select whether events are independent or mutually exclusive.
  3. Review joint and disjunctive probabilities.

The Mathematical Formula & Variables

P(A and B) = P(A) * P(B); P(A or B) = P(A) + P(B) - P(A and B)

Step-by-Step Worked Example

Scenario: Independent events with P(A) = 0.40 and P(B) = 0.30.

  1. Intersection P(A and B) = 0.40 * 0.30 = 0.12 (12%).
  2. Union P(A or B) = 0.40 + 0.30 - 0.12 = 0.58 (58%).

Result: 12.0% (P of both occurring)

Frequently Asked Questions

What are mutually exclusive events?

Events that cannot happen simultaneously (e.g. flipping heads and tails on a single coin toss). P(A and B) is always 0.