Conditional probability
Calculate conditional probability and see the working behind your result.
Inputs
Use the units shown—
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Formula & explanation
P(A|B) = P(A∩B)/P(B)
Variables & units
- P(A and B)
- Numeric value · minimum 0, maximum 1
- P(B)
- Numeric value · minimum 0.000001, maximum 1
Worked example
P(A∩B)=0.2 and P(B)=0.5 give P(A|B)=0.4.
Assumptions
P(B) must be positive.
Formula version 1.0.0. JavaScript floating-point arithmetic applies. Results display up to 6 decimal places; stored values retain available precision. Use the units shown.
Practice with an example
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