Union Probability
Find the probability that at least one of two events occurs.
Your numbers
Probability of A or B
Use consistent units. The result follows the assumptions you enter.
Scenario comparison
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Formula
P(A∪B)=P(A)+P(B)−P(A∩B)
Find the probability that at least one of two events occurs.
Worked example
- P(A) (%)
- 30
- P(B) (%)
- 40
- P(A and B) (%)
- 10
- Probability of A or B
- 60 %
Scope and limitations
Use consistent units. The result follows the assumptions you enter.
Inputs are checked for missing values and allowed ranges. A result outside the finite numeric range is not displayed. Rounding affects display, while the calculation uses the model’s numeric precision.
Check your units and assumptions before relying on a result. Changing a label does not convert a currency or physical unit.
Formula version: 151c9c1f5ea9 · Example checked: