This should be 1mm (width) by 1mm (height) size

This is 10 1mm x 1mm divs, so it should be 10mm (width) by 1mm (height) size

This should be 10mm (width) by 10mm (height) size.

This should be 1cm (width) by 1cm (height) size. So, same width as the line above.

This should be 2.54cm (width) by 2.54cm (height) size.

This should be 1in (width) by 1in (height) size. So, same size as above.