What is the formula for the probability of A OR B?
P(A or B) = P(A) + P(B) - P(A and B).
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Free Probability Calculator | 1ClickTools
Calculate probability calculator instantly with P(A and B) = P(A) × P(B), P(A or B) = P(A) + P(B) - P(A and B), P(NOT A) = 1 - P(A).
Frequently Asked Questions
What is a probability complement?
The complement P(NOT A) is 1 - P(A), representing the probability that event A does NOT occur.
How accurate is the Probability Calculator?
All calculations are executed using standard mathematical algorithms directly in client-side JavaScript, ensuring double-precision floating-point accuracy without server-side rounding discrepancies.
Is my input data kept private when using the Probability Calculator?
Yes. 1ClickTools operates 100% locally in your web browser session. No personal data, financial values, or calculation inputs are ever uploaded, saved, or transmitted to any external servers.
Can I use this tool for commercial or academic projects?
Yes. 1ClickTools provides 100% free access for personal, academic, professional, and commercial use without subscription fees or usage caps.