Education & Math Tools

Probability Calculator

Enter favorable and total outcomes to calculate probability, plus combined AND/OR probability with a second event.

16.67%
P(A)
8.33%
P(A and B) — independent events
58.33%
P(A or B)

How to use this tool

  1. 1Enter favorable and total outcomes for event A.
  2. 2Enter the probability of event B.
  3. 3See P(A), P(A and B), and P(A or B).

Frequently asked questions

Does this assume independent events?+

Yes — the AND/OR calculations assume events A and B are statistically independent.