Last Updated: April 13, 2026
Probability Calculator
Free probability calculator. Calculate single event, multiple event, and conditional probability.
P(Event)
0%
Odds
β
P(at least once)
0%
P(not happening)
0%
π How We Calculate — Learn about our calculation methodology, data sources, and quality standards.
Frequently Asked Questions
What is probability?
Probability = favorable outcomes / total outcomes. It ranges from 0 (impossible) to 1 (certain).
Independent vs dependent events?
Independent: P(A and B) = P(A) Γ P(B). Dependent: the outcome of A affects P(B).
What are odds vs probability?
Probability: 3 out of 10 = 30%. Odds: 3 to 7 (favorable to unfavorable).