# Circular mil conversions

area conversions » circular mil conversionsThe online converter calculator on this page allows you to select the area/surface measurement unit you want to convert to starting from circular mils (cmil). To make a conversion starting from a unit of area other than circular mil, simply click on the "Reset" button.

## What is circular mil?

### Definition:

The circular mil is a unit of area in the Imperial and US customary systems of units equal to 5.067x10-10 square meters (1 circular mil = 5.067x10-10 m2), the standard derived unit of area in the International System of Units (SI). It is also equal to 5.067x10-6 square centimeters (cm2), or 0.0005067 square millimeters (mm2), or 506.7 square micrometers (μm2) or 506.7x106 square nanometers (nm2) (units of area in the SI), or about 0.7853 square mils (sq mil), or 7.853x10-7 square inches (sq in) or 5.454x10-9 square feet (sq ft), which are Imperial / US customary units of area.

The circular 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 circular mil is the area of a circle that is 1.0 mil in diameter.

The conversion formula between square mils and circular mils:

**Square Mils = π/4 × Circular Mils**

The circular mil is used to specify the area of the cross section of a cable or wire. For example, a wire size of 200 kcmil or 200 MCM is a wire that has a cross-section of 200,000 circular mils.

*Note:*

1 MCM = 1 kcmil = 1,000 circular mils

### Symbol:

cmil

### Plural:

circular mils

Below you can find a comprehensive list with conversions from circular mils to other (metric, imperial, or customary) area and surface measurement units.