Quote from article Q130050 in the Knowledge Base:
<quote>Microsoft Excel uses the font assigned in the Normal style as the basis for column widths. There is no direct way to assign exact column widths in inches/centimeters without trial and error.
Microsoft Excel uses the number of digits (specifically, the number of zeros) using the Normal style font as the measurement to determine column widths. (There are some fonts that have digits of different widths, but this is unusual.)
For example, using the default font, a column width of 10 means the column width needed to display 10 non-bold, non-italic, Arial 10-point zeros. On the Macintosh, this same column width is 10 non-bold, non-italic Geneva 10-point zeros. Microsoft Excel uses digits to determine column widths so that when you change the font for a style on a worksheet, the columns grow or shrink to display this number of digits in the column.<unquote>
The rest of the article gives some VBA methods to help you work with this issue.
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