Basic Probability Formula

Output: Press calculate

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Formula:P(A) = Number of favorable outcomes / Total number of outcomes

Understanding Basic Probability

The basic probability formula calculates the likelihood of a single event occurring, where P(A) represents the probability of event A happening. This is done by dividing the number of favorable outcomes by the total number of possible outcomes. The formula is useful in various fields such as statistics, gambling, weather forecasting, and any area that processes uncertain events.

Parameter usage:


Data validation

Both parameters must be non-negative, and total outcomes must be greater than zero. Additionally, favorable outcomes should not exceed total outcomes.


This formula provides a quick way to assess the probability of an event occurring, based on the ratio of favorable to total outcomes. It assumes that all outcomes are equally likely.

Tags: Probability, Mathematics, Statistics