Square Inch (in²)
The square inch (in²) is the area of a square with 1 inch sides: exactly 6.4516 cm².
Symbol: in² (ASCII: in2)
Quantity: area
SI relation: 1 in² = 0.00064516 m² (exact)
Derivation: 1 in² = (0.0254 m)² = 6.4516 × 10⁻⁴ m² = 6.4516 cm²
Exact: yes, by definition
Typical uses
- Pressure in psi (pounds per square inch)
- Piston, orifice and gasket areas
- ASTM D737 test head (38.3 cm² ≈ 5.94 in²)
Convert square inches to other units
| Conversion | 1 in² equals | Reverse |
|---|---|---|
| square inch to square meter | 0.00064516 m² | square meter to square inch |
| square inch to square centimeter | 6.4516 cm² | square centimeter to square inch |
| square inch to square foot | 0.006944444444 ft² | square foot to square inch |
| square inch to square millimeter | 645.16 mm² | square millimeter to square inch |
Open the Area Converter to convert any value between all units.
Sources
- Guide for the Use of the International System of Units (SI), NIST Special Publication 811, 2008 Edition, National Institute of Standards and Technology , Appendix B.8, "square inch (in²)".
Last reviewed: . Factors are stored exactly and computed with 50-digit decimal arithmetic. See how we verify conversion factors.
Cite this page
APA
Scientific Converters. (2026, October 15). Square Inch (in²). Retrieved October 17, 2026, from https://scientificconverters.com/units/square-inch/
IEEE
Scientific Converters, "Square Inch (in²)," scientificconverters.com. Accessed: Oct. 17, 2026. [Online]. Available: https://scientificconverters.com/units/square-inch/