What are Square Microinches?
A square microinch is the area of a square one microinch (a millionth of an inch) on each side, so it is one trillionth of a square inch (10⁻¹²). In metric terms that is about 0.00064516 square microns.
What are Square Inches?
A square inch is the area of a square one inch on each side, which is exactly 6.4516 square centimeters or 0.00064516 square meters.