Adrienne

Do you mean as in column widths, row heights, objects?

There is no option in Excel for these.

Windows Regional Settings can be changed from Metric to Imperial.

Otherwise............

Any object that is measured in inches or centimeters.....Text Box, Drawing
Object, List Box from the Forms Toolbar for instance or Comment Box size,
would be determined by the measurment system set in your Windows Regional
Settings.

Row heights are measured in points.  There are 72 points to an inch.

The number that appears in the Standard column width box is the average number
of digits 0-9 of the standard font that fit in a cell.

No relationship between the two.

If you want to use VBA to set height and width in mm....which you could
convert to inches.

Ole Erlandson has code for setting row and column dimensions.

http://www.erlandsendata.no/english/index.php?d=envbawssetrowcol

Gord Dibben Excel MVP