Probability = favorable outcomes / total outcomes. It ranges from 0 (impossible) to 1 (certain).

Independent vs dependent events?

Independent: P(A and B) = P(A) × 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).

Last Updated: April 13, 2026

Free probability calculator. Calculate single event, multiple event, and conditional probability.

Favorable Outcomes

Total Outcomes

Number of Trials

At least once in trials?

P(Event)

Odds

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P(at least once)

P(not happening)

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