Probability Calculator

Express equally likely outcomes as a fraction, decimal, and percent.

A simple probability reference for defined outcome counts.

Your inputs stay on your device

Calculate simple probability

live result

Favourable outcomes

Total outcomes

Probability

0.3

Percent

30%

Reduced fraction

3/10

This is the simple equally-likely-outcomes model, not a prediction of real-world events.

Context & Reference

For calculating a simple probability from defined outcomes.

calculator guide

Divides favourable outcomes by total equally likely outcomes and reduces the fraction.

Use this calculator with your own values, then review the clearly labelled result and copy it when you need it elsewhere.

The same result is shown as a decimal, percentage, and fraction.

10 favourable outcomes out of 40 total equals 25%.

It does not predict real-world events or betting outcomes.

This calculator runs locally in this browser. It does not predict real-world events or betting outcomes.

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