Please Note: This article is written for users of the following Microsoft Excel versions: 2007, 2010, 2013, 2016, 2019, and 2021. If you are using an earlier version (Excel 2003 or earlier), this tip may not work for you. For a version of this tip written specifically for earlier versions of Excel, click here: Using GEOMEAN with a Large List.

Using GEOMEAN with a Large List

Written by Allen Wyatt (last updated August 20, 2024)
This tip applies to Excel 2007, 2010, 2013, 2016, 2019, and 2021


Ken wrote about a problem he was having with the GEOMEAN function. When he attempts to use the function on a large number of values (3,500 rows of data), he gets a #NUM error value returned.

The GEOMEAN function is used to return the geometric mean of a series of values. The GEOMEAN of n numbers is the n-th root of the product of the numbers. For example, if there are four values in a series (A through D), then the product of those numbers is A * B * C * D, and the GEOMEAN is the fourth root of that product.

The #NUM error would be returned if any of three conditions were met: any of the values was equal to zero, any of the values was negative, or the limits of Excel were exceeded. It is likely that it is this last condition that Ken is running into, particularly if any of his 3,500 values are large.

Since GEOMEAN finds the product of the 3,500 numbers (multiplies them all by each other) and then takes the nth root, the product may easily be too large for Excel. The largest positive number in Excel is 9.99999999999999 * 10^307 (in scientific notation this is written as 9.99999999999999E+307). If the product gets larger than this number, you will get a #NUM error for the function.

The solution is to use logs to do the calculation. This is easiest to understand when you look at a transformation of the GEOMEAN function:

GEOMEAN = (X1*X2*X3*...*Xn)^ (1/n)
ln(GEOMEAN) = ln((X1*X2*X3*...*Xn)^ (1/n))
ln(GEOMEAN) = (1/n) * ln(X1*X2*X3*...*Xn)
ln(GEOMEAN) = (1/n) * (ln(X1)+ln(X2)+ln(X3)+...+ln(Xn))
ln(GEOMEAN) = average(ln(X1)+ln(X2)+ln(X3)+...+ln(Xn))
GEOMEAN = exp(average(ln(X1)+ln(X2)+ln(X3)+...+ln(Xn)))

If you follow through the above, you see that GEOMEAN is equivalent to the exponent of the average of the logs of the values. You can calculate the desired result by using the following array formula instead of the GEOMEAN function:

=EXP(AVERAGE(LN(A1:A3500)))

This assumes that the desired values are in the range A1:A3500. Since it is an array formula, you must enter it into a cell by using Ctrl+Shift+Enter.

ExcelTips is your source for cost-effective Microsoft Excel training. This tip (9328) applies to Microsoft Excel 2007, 2010, 2013, 2016, 2019, and 2021. You can find a version of this tip for the older menu interface of Excel here: Using GEOMEAN with a Large List.

Author Bio

Allen Wyatt

With more than 50 non-fiction books and numerous magazine articles to his credit, Allen Wyatt is an internationally recognized author. He is president of Sharon Parq Associates, a computer and publishing services company. ...

MORE FROM ALLEN

Printing XML Tags

Word 2003 allows you to use and save your information in XML format. If you want to, you can have Word print a document's ...

Discover More

Embedding an Excel Worksheet

Word and Excel are both integral parts of Microsoft's Office suite of applications. As such, Word allows you to embed ...

Discover More

Remembering Copies to Print

If you routinely need to print more than one copy of a document, you'll love the ideas presented in this tip. There's ...

Discover More

Create Custom Apps with VBA! Discover how to extend the capabilities of Office 365 applications with VBA programming. Written in clear terms and understandable language, the book includes systematic tutorials and contains both intermediate and advanced content for experienced VB developers. Designed to be comprehensive, the book addresses not just one Office application, but the entire Office suite. Check out Mastering VBA for Microsoft Office 365 today!

More ExcelTips (ribbon)

Converting to Hexadecimal

Excel allows you to easily convert values from decimal to other numbering systems, such as hexadecimal. This tip explains ...

Discover More

Returning an ANSI Value

Need to know the character value of the first character in a string? It's easy to do, without using a macro, by using the ...

Discover More

Returning Blanks or Asterisks from a Lookup

Want to return more than a value when doing a lookup? Here are a couple of ways to do it by adding an IF clause to your ...

Discover More
Subscribe

FREE SERVICE: Get tips like this every week in ExcelTips, a free productivity newsletter. Enter your address and click "Subscribe."

View most recent newsletter.

Comments

If you would like to add an image to your comment (not an avatar, but an image to help in making the point of your comment), include the characters [{fig}] (all 7 characters, in the sequence shown) in your comment text. You’ll be prompted to upload your image when you submit the comment. Maximum image size is 6Mpixels. Images larger than 600px wide or 1000px tall will be reduced. Up to three images may be included in a comment. All images are subject to review. Commenting privileges may be curtailed if inappropriate images are posted.

What is three more than 1?

There are currently no comments for this tip. (Be the first to leave your comment—just use the simple form above!)


This Site

Got a version of Excel that uses the ribbon interface (Excel 2007 or later)? This site is for you! If you use an earlier version of Excel, visit our ExcelTips site focusing on the menu interface.

Newest Tips
Subscribe

FREE SERVICE: Get tips like this every week in ExcelTips, a free productivity newsletter. Enter your address and click "Subscribe."

(Your e-mail address is not shared with anyone, ever.)

View the most recent newsletter.