WEIBULL.DIST
TheWEIBULL.DIST
function returns the Weibull distribution, which is commonly used in reliability analysis to model timetofailure data. It describes a range of possible times until failure for a product or process. The function returns the cumulative distribution function (CDF) if cumulative is TRUE, and the probability density function (PDF) if cumulative is FALSE.
 How to use
WEIBULL.DIST
formula?  Examples of using
WEIBULL.DIST
formula WEIBULL.DIST
formula not working? Similar formulas to
WEIBULL.DIST
Usage
Use the WEIBULL.DIST
formula with the syntax shown below, it has 3 required parameters and 1 optional parameter:
 x (required):
The value at which to evaluate the function; must be greater than or equal to zero.  shape (required):
The shape parameter of the distribution; must be greater than zero.  scale (required):
The scale parameter of the distribution; must be greater than zero.  cumulative (optional):
A logical value that determines the form of the function to be returned; TRUE for the CDF, FALSE for the PDF. If omitted, defaults to TRUE.
Examples
Here are a few example use cases that explain how to use theWEIBULL.DIST
formula in Google Sheets.
Calculate the probability of failure within a given time frame
Suppose you want to know the probability that a product will fail within the first 1000 hours of use, given that its Weibull shape parameter is 1.5 and its scale parameter is 500 hours. You can use WEIBULL.DIST
to calculate this probability.
Model the reliability of a system
If you know the Weibull distribution parameters for a system, you can use them to model its reliability over time. For example, you can use WEIBULL.DIST
to calculate the probability that a system will still be operational after a certain amount of time has elapsed.
Determine the expected value of a sample
If you have a sample of data that is known to follow a Weibull distribution, you can use WEIBULL.DIST
to determine its expected value. This can be useful in predicting future values or comparing different samples.
Common Mistakes
WEIBULL.DIST
not working? Here are some common mistakes people make when using the WEIBULL.DIST
Google Sheets Formula:
Forgetting to convert units
If your data is in hours but you're using a scale parameter that assumes minutes, your results will be incorrect. Make sure your units are consistent throughout your analysis.
Using the wrong type of distribution
Make sure the Weibull distribution is appropriate for your data. If your data follows a different distribution, using the WEIBULL.DIST
function will give you incorrect results.
Related Formulas
The following functions are similar to WEIBULL.DIST
or are often used with it in a formula:

WEIBULL
The
WEIBULL
function returns the Weibull distribution, which is a continuous probability distribution that is often used to model failure rates of systems over time. The function takes four arguments:x
, which is the value at which to evaluate the distribution;shape
, which is the shape parameter of the distribution;scale
, which is the scale parameter of the distribution; andcumulative
, which is a logical value indicating whether to return the cumulative distribution function (TRUE) or the probability density function (FALSE). 
EXPON.DIST
The EXPON.DIST function returns the exponential distribution of a specified random variable, x, given a specified lambda, LAMBDA. The exponential distribution is commonly used to model the time between events in a Poisson process. The function returns the probability density function or the cumulative distribution function of the exponential distribution depending on whether the cumulative argument is set to TRUE or FALSE. This function is useful for analyzing reliability data and can be used to determine the probability that a component will fail before a certain time.
Learn More
You can learn more about the WEIBULL.DIST
Google Sheets function on Google Support.