Set Excel 2013 cell size in millimeters (or inches for those relics living in US)

• Open new excel sheet.
• Select desired paper size (A4 or A3... of course), orientation and set margins.
• Open View tab.
• Click Page Layout under Workbook Views.
• Press Ctrl+A.
• Open Home tab.
• Click Format under Cells.
• Select Row height and enter desired size with mm suffix (or "in" for rednecks)
• Click Format under Cells
• Select Column width and enter desired size.
• Open View tab.
• Click Normal under Workbook Views.
• Done.