Square_inch
A square inch (plural: square inches) is a unit of area, equal to the area of a square with sides of one inch. The following symbols are used to denote square inches:
- square in
- sq inches, sq inch, sq in
- inches/-2, inch/-2, in/-2
- inches^2, inch^2, in^2
- inches2, inch2, in2 (also denoted by "2)
- historic engineering drawings □″ (number with a square & a double apostrophe, both as an exponent)
The square inch is a common unit of measurement in the United States and the United Kingdom. A common unit of pressure, pound per square inch (psi) is derived from this unit of area.