Math
Probability Calculator
Four modes: P(A), P(A∪B), P(A∩B), P(A|B). Result as fraction and percentage.
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Enter values to calculate probability
What does Probability Calculator?
Calculate probability of events, including compound and conditional probability.
How to use Probability Calculator?
- Enter the number of favorable outcomes.
- Enter the total number of possible outcomes.
- View the probability as a fraction, decimal, and percentage.
Key features
- Calculates simple, compound, and conditional probabilities.
- Displays results as fraction, decimal, and percentage.
- Supports multiple event combinations.
Frequently asked questions
What is probability?
Probability is the likelihood of an event occurring, expressed as a number between 0 and 1.
What is complementary probability?
The complementary probability is 1 minus the probability of the event — it represents the chance the event does NOT occur.
Is this tool free?
Yes, this tool is completely free and requires no registration.
Is my data saved?
No. All calculations happen in your browser only — no data is sent to any server.