BETAINV function

Returns the inverse of the cumulative beta probability density function for a specified beta distribution. That is, if probability = BETADIST(x,...), then BETAINV(probability,...) = x. The beta distribution can be used in project planning to model probable completion times given an expected completion time and variability.

Important   This function has been replaced with one or more new functions that may provide improved accuracy and whose names better reflect their usage. Although this function is still available for backward compatibility, you should consider using the new functions from now on, because this function may not be available in future versions of Excel.

For more information about the new function, see BETA.INV function.



The BETAINV function syntax has the following arguments:

  • Probability     Required. A probability associated with the beta distribution.

  • Alpha     Required. A parameter of the distribution.

  • Beta     Required. A parameter the distribution.

  • A     Optional. A lower bound to the interval of x.

  • B     Optional. An upper bound to the interval of x.


  • If any argument is nonnumeric, BETAINV returns the #VALUE! error value.

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

  • If probability ≤ 0 or probability > 1, BETAINV returns the #NUM! error value.

  • If you omit values for A and B, BETAINV uses the standard cumulative beta distribution, so that A = 0 and B = 1.

Given a value for probability, BETAINV seeks that value x such that BETADIST(x, alpha, beta, A, B) = probability. Thus, precision of BETAINV depends on precision of BETADIST.


Copy the example data in the following table, and paste it in cell A1 of a new Excel worksheet. For formulas to show results, select them, press F2, and then press Enter. If you need to, you can adjust the column widths to see all the data.




Probability associated with the beta distribution


Parameter of the distribution


Parameter of the distribution


Lower bound


Upper bound





Inverse of the cumulative beta probability density function for the parameters above


Applies To: Excel 2016, Excel 2010, Excel Starter, Excel 2013, Excel Online, Excel 2016 for Mac, Excel for Mac 2011, 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!

Change language