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.

Equivalence with other units of area
1 square inch (assuming an international inch) is equal to: (the overbars indicate repeating decimals)
 * 0.006 9 square feet (1 square foot is equal to 144 square inches)
 * 0.000 7 square yards (1 square yard is equal to 1,296 square inches)
 * 6.4516 square centimetres (1 square centimetre is equal to 0.155 000 310... square inches)
 * 0.000 645 16 square metres (1 square metre is equal to 1,550.003 100... square inches)

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