Free · Math · Statistics & Probability

Probability Calculator

Calculate event probability, odds, complements, and independent two-event combinations.

  • Calculation method included
  • Private in your browser
  • No signup
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Calculator inputs

Enter your values

Result

Your calculation

P(A)
30%
3 ÷ 10
P(not A)
70%
Odds in favour
3 : 7
P(A and B), independent
12%
P(A or B), independent
58%

How to use this calculator

  1. Enter the known values using the units shown.
  2. Choose the calculation you want when more than one method is available.
  3. Calculate, then review the result and the worked formula together.

Private by default

Inputs and results stay in this browser tab. Bookify does not upload or store the values you enter.

Explore statistics & probability or browse all statistics calculators.