Convert Circular Mils to Square Feet

Convert Circular Mils (cmil) to Square Feet (ft²) instantly and accurately.

Circular Mils (cmil)
Square Feet (ft²)

Conversion Formula

ft² = cmil × 5.454153912e-9

About Circular Mils

A circular mil (cmil) is a unit used in electrical engineering to specify the cross-sectional area of round wires and cables. Equal to the area of a circle with a diameter of exactly one thou (one thousandth of an inch) - approximately 5.067 × 10⁻¹⁰ m² - it simplifies wire calculations: the cross-sectional area in cmil equals the wire diameter in mils, squared. US electrical codes (NEC/NEMA) specify conductor sizes in circular mils, and large cables are rated in thousands of circular mils (kcmil or MCM). A 12 AWG wire, common in US household wiring, has a cross-section of 6,530 cmil.

About Square Feet

A square foot (ft²) is an imperial unit of area equal to a square with sides of one foot (12 in × 12 in or 144 in²). It is the standard for measuring floor space in the United States and some other countries. A typical bedroom is 100-150 ft², and the average American house is roughly 2,000-2,500 ft². This unit dominates real estate listings, flooring sales, and construction in countries using imperial measurements.

Quick Reference Table

Circular Mils (cmil)Square Feet (ft²)
1 cmil5.454 × 10-9 ft²
2 cmil1.091 × 10-8 ft²
5 cmil2.727 × 10-8 ft²
10 cmil5.454 × 10-8 ft²
25 cmil1.364 × 10-7 ft²
50 cmil2.727 × 10-7 ft²
100 cmil5.454 × 10-7 ft²

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