SIMPLE PROBABILITY

This probability calculator finds the chance of an event from favourable outcomes and total outcomes.

It shows the result as a simplified fraction, decimal, percentage and odds.

Enter the number of favourable outcomes and the total number of possible outcomes.

Press SOLVE to see the probability, percentage and odds for the event.

probability = favourable outcomes ÷ total outcomes

The total outcomes should include every equally likely possible outcome.

P = 3 ÷ 10 = 0.3

This is 3/10, 30%, and odds of 3:7 for the event.

Favourable outcomes are the outcomes that count as success for your event.

For example, rolling a 6 on one die has 1 favourable outcome.

Total outcomes are all possible results in the sample space.

For one fair die, there are 6 total outcomes. For a deck of cards, there are 52 cards.

Odds compare favourable outcomes with outcomes against the event.

odds for = favourable : total − favourable

Students use it for probability homework, revision and checking answers.

Teachers and tutors use it to explain sample spaces, fractions and percentages.

Common searches include probability calculator, simple probability calculator and probability formula.

This page gives a calculator, formula, worked example, odds and related probability tools.

No. If favourable outcomes are higher than total outcomes, the inputs need checking.

The calculator warns when favourable outcomes exceed total outcomes.