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Probability Calculator
Calculate single event, joint, and conditional probabilities for independent events.
✓ Free✓ No signup✓ Privacy first✓ Runs in your browser
P(A and B) [Independent]
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P(A or B) [Mutually Exclusive]
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P(A or B) [Independent]
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Probability Calculator · secure stats checks
How it works
Calculate odds in three steps
1. Enter event probabilities
Input the probability of event A and event B as decimal values (0 to 1).
2. Calculate metrics
Start the tool to evaluate joint, mutually exclusive, and independent probabilities.
3. Inspect output values
Review the calculated probabilities, including P(A and B) and P(A or B).
FAQ
Common questions
Probability is the mathematical likelihood of an event occurring, represented as a value between 0 (impossible) and 1 (certain).
No, all calculations run locally in your browser, keeping your calculations secure.
Independent events can happen at the same time without affecting each other, while mutually exclusive events cannot occur simultaneously.
Multiply the decimal probability by 100 (for example, a probability of 0.25 converts to a 25% chance of occurring).
Keep going
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About the Probability Calculator
Calculating joint and independent event probabilities for statistics assignments, risk models, or decision audits shouldn’t require complex software. This offline calculator processes your values locally, letting you perform calculations and check formulas in seconds.
Benefits
- Calculate probability locally — Run statistical checks in your browser without external server calls.
- Support core event types — Calculate independent, mutually exclusive, and joint probabilities.
- Display multiple formulas — Inspect different probability outputs simultaneously.
- Prevent input errors — Scan inputs to ensure values remain between 0 and 1.
Privacy
All calculations run locally in your browser window and no inputs are saved.