About this probability calculator
Estimate simple and combined probabilities from a favorable count, total count, and a second percentage probability.
How to use it
Enter the values requested by the calculator. Results update in your browser as you change the inputs. Review the assumptions shown on the calculator before using the result.
Formula
P(A and B) = P(A) × P(B) when treated as independent
Example
The combined calculations assume the events used in the formula are independent.
Frequently asked questions
What does the probability calculator show?
Estimate simple and combined probabilities from a favorable count, total count, and a second percentage probability.
Are the results exact?
The result is calculated from the inputs and assumptions shown on this page. For important financial, health, tax, or legal decisions, verify the result with an appropriate professional or authoritative source.