Learning focus 1
Provide the probability of each event as a decimal or fraction.
Free online calculator
Probability Calculator
Calculate probabilities for single events, combined events (AND/OR), and conditional probability. Get clear step-by-step reasoning.
Step-by-step solutions
Clear, detailed explanations
Instant results
Accurate answers in seconds
Free to use
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How to Use the Probability Calculator
1
Enter probabilities
Provide the probability of each event as a decimal or fraction.
2
Choose the operation
AND (intersection), OR (union), or conditional (given).
3
Apply probability rules
We use the multiplication and addition rules correctly.
Example
What the Probability Calculator Helps You Understand
Calculate probabilities for single events, combined events (AND/OR), and conditional probability. Get clear step-by-step reasoning.
Learning focus 2
AND (intersection), OR (union), or conditional (given).
Learning focus 3
We use the multiplication and addition rules correctly.
Input tips
- • Provide the probability of each event as a decimal or fraction.
- • Yes. For conditional probability, enter P(A) and P(B|A) and the calculator applies Bayes' rule.
Common mistakes to avoid
- • Adding probabilities for events that are not mutually exclusive.
- • Multiplying dependent-event probabilities without a conditional probability.
Frequently Asked Questions
Can it handle dependent events?
Yes. For conditional probability, enter P(A) and P(B|A) and the calculator applies Bayes' rule.
What about mutually exclusive events?
For OR with mutually exclusive events, the probabilities simply add. The calculator detects this automatically.