# Square mil conversions

The square mil conversion selector here selects the area/surface measurement unit to convert to starting from square mils (sq mil). To make a conversion starting from a unit of area other than square mil, simply click on the "Reset" button.

## About square mil

The **square mil** is a unit of area in the Imperial and US customary systems of units equal to 6.4516 × 10^{-10} square meters (1 square mil = 6.4516 × 10^{-10} m^{2}), the standard derived unit of area in the International System of Units (SI).

The square mil (sq mil) is also equal to 6.4516 × 10^{-6} square centimeters (cm^{2}), or 6.4516 × 10^{-4} square millimeters (mm^{2}), or 645.16 square micrometers (μm^{2}) or 6.4516 × 10^{8} square nanometers (nm^{2}) (units of area in the SI), or about 1.273 circular mils (cmil), or 10^{-6} square inches (sq in) or 6.94444444 × 10^{-9} square feet (sq ft), which are Imperial / US customary units of area.

The square mil (sq mil) is an Imperial / US customary unit of area. The mil is a unit of length in the Imperial and US customary systems of units. An area of 1.0 square mil is the area of a square that is 1.0 mil on each side.

The conversion formula between square mils and circular mils:

Square Mils = π/4 × Circular Mils

Symbol: sq mil

Plural: square mils