sq in

Units & Measurements abbreviation · US Customary and Imperial Unit

sq in
Stands forSquare inch
CategoriesUnits & Measurements

sq in stands for Square inch, a US customary and imperial unit abbreviation.

Area of a square one inch on each side, about 6.45 square centimeters. It is most familiar inside psi, pounds per square inch, and in specifications for small areas such as solar cells, gaskets and print sizes.

Example: The piston face has an area of 3.14 sq in, so 100 psi produces about 314 pounds of force.

Usage notes

Also written in² or sq. in. A square foot contains 144 sq in. Tire, air compressor and hydraulic pressures are all expressed as force per square inch. In printing, photos are sized in inches but priced per square inch for large-format jobs.

More US customary and imperial unit abbreviations

  • ac – Acre
  • ac-ft – Acre-foot
  • bbl – Barrel (oil)
  • bd ft – Board foot
  • bu – Bushel
  • CCF – Hundred cubic feet
  • ch – Chain
  • cu ft – Cubic foot
  • cu in – Cubic inch
  • cu yd – Cubic yard
  • cwt – Hundredweight
  • dr – Dram

See all 43 US customary and imperial unit abbreviations →

Edited by the AbbreviationList.com team. Spotted an error or a missing meaning? Contact us.