WEIBULL function

Returns the Weibull distribution. Use this distribution in reliability analysis, such as calculating a device's mean time to failure.

Syntax

WEIBULL(x,alpha,beta,cumulative)

X     is the value at which to evaluate the function.

Alpha     is a parameter to the distribution.

Beta     is a parameter to the distribution.

Cumulative     determines the form of the function.

Remarks

  • If x, alpha, or beta is nonnumeric, WEIBULL returns the #VALUE! error value.

  • If x < 0, WEIBULL returns the #NUM! error value.

  • If alpha ≤ 0 or if beta ≤ 0, WEIBULL returns the #NUM! error value.

  • The equation for the Weibull cumulative distribution function is:

    Equation

  • The equation for the Weibull probability density function is:

    Equation

  • When alpha = 1, WEIBULL returns the exponential distribution with:

    Equation

Example

The example may be easier to understand if you copy it to a blank worksheet.

How to copy an example

  1. Create a blank workbook or worksheet.

  2. Select the example in the Help topic.

    Note   Do not select the row or column headers.

    Selecting an example from Help

    Selecting an example from Help

  3. Press CTRL+C.

  4. In the worksheet, select cell A1, and press CTRL+V.

  5. To switch between viewing the results and viewing the formulas that return the results, press CTRL+` (grave accent), or on the Formulas tab, in the Formula Auditing group, click the Show Formulas button.

1

2

3

4

A

B

Data

Description

105

Value at which to evaluate the function

20

Alpha parameter to the distribution

100

Beta parameter to the distribution

Formula

Description (Result)

=WEIBULL(A2,A3,A4,TRUE)

Weibull cumulative distribution function for the terms above (0.929581)

=WEIBULL(A2,A3,A4,FALSE)

Weibull probability density function for the terms above (0.035589)

Applies To: Excel 2007



Was this information helpful?

Yes No

How can we improve it?

255 characters remaining

To protect your privacy, please do not include contact information in your feedback. Review our privacy policy.

Thank you for your feedback!

Support resources

Change language