Calculate both, inclusive OR, exactly one and neither for two events under an explicit relationship model.
How to use this tool
- Choose the event or model and review the assumptions below.
- Enter the labeled inputs. Probability inputs are percentages from 0 to 100, not decimal fractions.
- Select Calculate and read the labeled outputs.
- Change an input and calculate again; Reset restores the example inputs.
Calculation method
P(A or B)=P(A)+P(B)−P(A and B). Neither=1−P(A or B). Exactly one=P(A)+P(B)−2P(A and B).
Assumptions and limits
A two-event set-algebra workspace. Independence and exclusivity are explicit alternative models. Known intersections must produce a feasible two-by-two table. For reversing conditionals, use the existing Conditional Probability Calculator.
Worked example
Marginals 40% and 50% with a 20% intersection give union 70%, exactly one 50% and neither 30%. Invalid joint tables are rejected.
Worked reading and practical questions
Browse Statistics calculators or explore other tools on the GreenCalc homepage.
Frequently asked questions
What does this calculator assume?
A two-event set-algebra workspace. Independence and exclusivity are explicit alternative models. Known intersections must produce a feasible two-by-two table. For reversing conditionals, use the existing Conditional Probability Calculator.
How do I enter and update the inputs?
Use the labeled fields, then select Calculate. Percent fields use 0 to 100. After editing, calculate again; Reset restores the example inputs.