Probability Calculator
Calculate simple probability from favorable and total outcomes quickly with clear inputs and an instant result on mobile or desktop.
Probability Calculator
Tool inputs are not stored, and private values stay out of analytics.
Result
How it works
Enter the requested values in the Probability Calculator, then calculate to see the result and its useful supporting details.
The calculator uses this method: divide favorable outcomes by all possible outcomes. Processing happens in the browser, so you can adjust values, recalculate, and review the output before copying it.
Examples
Worked example
Two favorable outcomes from six possibilities gives 33.33%.
Compare inputs
Change one value in the Probability Calculator and compare the new output to understand its effect.
FAQ
How do I use the Probability Calculator?
Enter the values shown in the form, check any units, then select the calculate button.
Does the calculator save entered numbers?
No. The calculation runs in the browser and field values are not sent as analytics data.
How accurate is the result?
Check inputs and rounding first, and verify official or critical decisions with the appropriate source.