Probability Calculator
Calculate the probability of events, combined probabilities, and odds.
Single Event Probability
Combined Probability (Independent Events)
Formula
P(event) = favorable outcomes / total outcomes — P(A and B) = P(A) × P(B) for independent eventsProbability Basics
Probability = (favorable outcomes) ÷ (total possible outcomes). It ranges from 0 (impossible) to 1 (certain). Multiply by 100 for a percentage.
Frequently Asked Questions
What is probability?
Probability measures the likelihood of an event, from 0 (impossible) to 1 (certain). A coin flip has probability 0.5 or 50%.
What does 'independent events' mean?
Independent events don't affect each other. A coin flip doesn't affect the next flip. For independent events, P(A and B) = P(A) × P(B).