Exponential distribution calculator
Model waiting time between events occurring at a constant rate λ.
How to use this page
- Choose density, CDF, upper tail or quantile.
- Enter a positive λ.
- Enter x or probability q.
What this page does not do: The model does not fit a changing event rate or a waiting process with memory.
Further reading
The exponential distribution models a non-negative waiting time under a constant event rate. The rate λ is the reciprocal of the mean waiting time.
Its memoryless property means that the remaining waiting time does not depend on how long you have already waited.
Frequently asked questions
How do I choose λ?
If the mean waiting time is m, then λ=1/m in the same time unit.
Is density a point probability?
No. For a continuous variable, probability at one exact point is zero.
See also
ACF and PACF autocorrelation calculator
Calculate ACF and PACF across time-series lags. Review the chart, reference bounds and coefficient table.
Adjusted R-squared calculator
Convert R² to adjusted R² using the number of observations and predictors in a regression model.
Beta distribution calculator
Calculate beta density, CDF, upper tail and quantile together with its mean and variance.