Handling Negative Numbers in a Complex Custom Format

Douglas is having some problems getting his head around a custom format he needs. He has created a custom format that displays large numbers the way he wants, such that $1,000,000 is displayed as $1.0M and $1,000 is displayed as $1.0K. This format is as follows: [>1000000]$#.0,,"M";[>1000]$#.0,"K";$#,##0.0. Douglas wants to know how to adjust the custom format so that negative numbers appear in this same fashion, but in red with parentheses around them, like ($1.0K).

Unfortunately, what you want to do is not possible with a single custom format. The reason is because a single custom format can only have four conditions, each separated by a semicolon. This is the general syntax of a custom format:

positive; negative; zero; text

Note that the first format is used when the value is positive, the second when it is negative, the third when the value is exactly zero, and the fourth when the value is text. While this is the general syntax for custom formats, you can "fudge" the formats a little in the way you are doing. Consider the format you are using:

[>1000000]$#.0,,"M";[>1000]$#.0,"K";$#,##0.0

Note that according to the general syntax, the format before the first semicolon would be used for positive values, the next format for negative values, and the third for zero values. However, this is not the way in which Excel translates this custom format. It translates it as "if greater than 1,000,000, do this; if greater than 1,000 do this; else do this". There is no positive or negative connotation in the format; in fact, any negative values are treated to the default treatment, which is the third format.

What you are trying to do is to define two positive conditions (one for millions and one for thousands) and two negative conditions (again, for millions and thousands). This cannot be done in a single custom format, regardless of how you try to put it together. Instead, you should use two custom formats, such as these:

[>=1000000]$#.0,,"M ";[>=1000]$#.0,"K ";$#,##0.0
[Red][<=-1000000]($#.0,,"M");[Red][<=-1000]($#.0,"K");[Red]($#,##0.0)

The first format is to be used in the case of positive values; it is a variation on the original format suggested at the first of the tip. The second format is to be used with negative values. These custom formats will need to be manually applied, based upon the value in the cell.

This may seem like a lot of work to go through to get the formatting you want. It is possible to create a macro that applies the formats, but the macro would not be a trivial endeavor. It would need to check what the value in the cell is, pick the proper format, construct the format, stuff it into the custom format for the cell, and then move on to the next cell.

Some people may also think you could use conditional formatting in this case. Conditional formatting doesn't allow you to modify the presentation of the number in the cell, however. While you can check for the value (more than a thousand or a million, for instance), you cannot then divide, round, and add a suffix to the value in the cell. Nor can you do things like add parentheses to negative values.

ExcelTips is your source for cost-effective Microsoft Excel training. This tip (10226) applies to Microsoft Excel 97, 2000, 2002, and 2003. You can find a version of this tip for the ribbon interface of Excel (Excel 2007 and later) here: Handling Negative Numbers in a Complex Custom Format.