Conditional Probability Calculator
Calculate conditional probabilities using Bayes' theorem and probability rules
About this calculator
A Conditional Probability Calculator helps you determine the probability of an event occurring given that another related event has already happened. Using Bayes' theorem and fundamental probability rules, this tool calculates P(A|B) - the probability of event A given event B has occurred. This calculator is essential for statistical analysis, medical diagnosis, quality control, risk assessment, and decision-making processes where prior information affects the likelihood of future outcomes.
How to use
Enter the probability of the first event (P(A)), the probability of the second event (P(B)), and the probability of both events occurring together (P(A and B)). The calculator will compute the conditional probability P(A|B) using the formula P(A|B) = P(A and B) / P(B), providing instant results for your probability analysis.
Frequently asked questions
What is conditional probability?
Conditional probability is the likelihood of an event occurring given that another event has already happened, expressed as P(A|B).
When do I use Bayes' theorem?
Use Bayes' theorem when you need to update probabilities based on new evidence or prior knowledge of related events.
Can conditional probability exceed 1?
No, conditional probability is always between 0 and 1, representing impossible to certain likelihood given the condition.