Conditional Probability Calculator

Find P(A given B).

P(A | B) 0.4

P(A | B) (%) 40

Formula: P(A|B) = P(A and B) ÷ P(B)

Step-by-step with your numbers:

1. Values used:

2. P(A and B) = 0.2

3. P(B) = 0.5

5. P(A | B) = P(A and B) / P(B) = 0.2 / 0.5 = 0.4

6. P(A | B) = 40%

Did we solve your problem today?

Conditional probability is the chance of A given that B happened.

The math behind it

P(A | B) = P(A and B) ÷ P(B).

0.2 ÷ 0.5 → 0.4 (40%).

Independent events?

Then P(A|B) = P(A).