Probability Calculator

Calculate basic probability from favorable and total outcomes, then view the result as a decimal, fraction, percentage, and complement probability.

Formula:
P(A) = favorable / total

Result will appear here.
Metric Value

Privacy: calculations run locally in your browser. No inputs are stored or transmitted.

How it works

This tool computes the probability of an event from a simple count model:
P(A) = favorable outcomes / total outcomes

Examples

  • 3 favorable out of 10 total → probability = 0.3
  • Percentage form = 30%
  • Complement probability = 1 − P(A)

FAQ

  • What does this probability calculator compute?

    It computes basic probability from favorable outcomes divided by total outcomes, and also shows complement probability and percentage form.

  • What is the formula for basic probability?

    Probability = favorable outcomes / total outcomes.

  • Can favorable outcomes be larger than total outcomes?

    In a standard basic probability setup, favorable outcomes should be between 0 and total outcomes inclusive.

  • Are calculations stored?

    No. Everything runs locally in your browser.

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