How to Measure Column Width and Height in Milimeter?

Hi All,

I want to print on stickers from Excel using VBA. May i know how can i set the column width, row height and Margins in Millimeters?

I also attached the pdf file with images of sticker.

Lable Width 20mm
Lable Height 8mm
Left Margin 8.8mm
Lop margin 22mm
Gap between stickers 2.95mm

Thanks in advance for your help,
Ramana.