Square inch conversions
The square inch conversion selector selects the area/surface measurement unit to convert to starting from square inches (sq in). To make a conversion starting from a unit of area other than square inch, simply click on the "Reset" button.
About square inch
The square inch is a unit of area in the Imperial and US customary systems of units equal to 6.4516 × 10-4 square meter (1 sq in = 6.4516 × 10-4 m2), the standard derived unit of area in the International System of Units (SI).
One square inch (sq in) is also equal to 6.4516 square centimeters (cm2), or 645.16 square millimeters (mm2) or 6.4516 × 108 square micrometers (μm2) (units of area in the SI), or 1.273239 circular inches, or 7.71604938 × 10-4 square yards (sq yd) or 0.00694444444 square feet (sq ft), which are Imperial / US customary units of area.
The square inch (sq in) is an Imperial / US customary unit of area. The inch (in) is a unit of length in the Imperial and US customary systems of units. An area of 1.0 square inch is the area of a square that is 1.0 inch on each side.
The conversion formula between square inches and circular inches:
Square Inches = π/4 × Circular Inches
Symbol: sq in
Plural: square inches