Conditional probability calculator
Enter probabilities as values from 0 to 1.
Branch probabilities
Bars show the calculated outcomes.
Calculation branches
| Event | Probability |
|---|---|
| Fill in the fields above — the result is computed on this page. | |
How do I use this page?
- Enter inputs.
- Check the branches and formula.
What this page does not do: The result assumes the supplied conditional probabilities are correct; repeated-trial mode assumes independence.
Further reading
Theory — how is conditional probability calculated?
This calculator finds the probability of one event occurring given that another event is already known to have happened. Inputs are entered as decimal values between 0 and 1, so 25% becomes 0.25. The calculation relies on the multiplication rule and the complement of an event, with every intermediate step displayed alongside the final result.
Frequently asked questions
Can I enter percentages?
See also
A/B test calculator
Compare two proportions in an A/B test. Calculate conversion rates, difference, uplift, z score, p value and c
A/B test planning — sample size, MDE and duration
Plan a two-proportion experiment, estimate detectable effect and traffic duration.
ACF and PACF autocorrelation calculator
Calculate ACF and PACF across time-series lags. Review the chart, reference bounds and coefficient table.