Square inch
| square inch | |
|---|---|
 Engineering paper, with the cropped scan depicting 24 square inches (25 smaller squares compose 1 square inch) | |
| General information | |
| Unit system | Imperial, United States customary units |
| Unit of | area |
| Symbol | in2, sq in |
| Conversions | |
| 1 in2 in ... | ... is equal to ... |
| Imperial/US |
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| SI units |
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A square inch (plural: square inches) is a unit of area, equal to the area of a square with sides of one inch. The square inch is a common unit of measurement in the United States and the United Kingdom. Pounds per square inch (psi), a unit of pressure, are derived from this unit of area.