The Probability Calculator helps determine the likelihood of an event when the required outcomes and total possible outcomes are known. Probability is a number from 0 to 1, or equivalently from 0% to 100%, under the usual definition for an event.
Basic Probability Formula
When outcomes are equally likely, P(Event) = Favorable Outcomes Γ· Total Possible Outcomes.
How to Use the Calculator
- Identify the event you want to measure.
- Enter the favorable outcomes and total possible outcomes requested by the tool.
- Calculate the probability.
- Convert the result to a percentage if a percentage is easier to interpret.
Example
A fair six-sided die has six possible outcomes. The probability of rolling a 4 is 1 Γ· 6, which is approximately 0.1667, or 16.67%.
Reading Probability Results
A probability of 0 means the event cannot occur under the stated model, while 1 means it is certain. Values between them describe different likelihoods. The basic favorable-outcomes formula should only be used when the listed outcomes are equally likely.