Convert Circular Mil (circ mil) to Square Mil (mil²) instantly.
Circular Mil to Square Mil conversion
1 Circular Mil (circ mil) = 0.78539816 Square Mil (mil²). To convert Circular Mil to Square Mil, multiply the value by 0.78539816.
| Circular Mil (circ mil) | Square Mil (mil²) |
|---|---|
| 1 | 0.78539816 |
| 2 | 1.5707963 |
| 5 | 3.9269908 |
| 10 | 7.8539816 |
| 25 | 19.634954 |
| 50 | 39.269908 |
| 100 | 78.539816 |
| 1000 | 785.39816 |
Frequently asked questions
How many Square Mil are in one Circular Mil?
One Circular Mil (circ mil) equals 0.78539816 Square Mil (mil²).
How do I convert Circular Mil to Square Mil?
To convert Circular Mil to Square Mil, multiply the value by 0.78539816.
What is 10 Circular Mil in Square Mil?
10 Circular Mil = 7.8539816 Square Mil.
About these units
Circular Mil (circ mil)
A circular mil is defined as the area of a circle with a diameter of exactly one mil. Because wires and cables have circular cross-sections, the circular mil has become a standard unit in electrical engineering for specifying conductor sizes. One circular mil simplifies calculations because area scales directly with the square of wire diameter without needing π in computations. For example, doubling a wire's diameter increases its circular-mil area fourfold. This makes circular mils extremely convenient for determining ampacity, resistance, and voltage drop in electrical conductors. Even though SI units are common elsewhere, the circular mil remains entrenched in North American electrical codes.
Square Mil (mil²)
A square mil equals the area of a square one mil (0.001 inch) on each side, producing an area of one-millionth of a square inch. This tiny unit appears in microfabrication, thin-film manufacturing, and fine electronic component design. Engineers rely on mils and mil² for PCB trace design, wire bonding pads, and micro-mechanical parts. Despite modern efforts to shift toward metric units, mils remain deeply embedded in American electronics manufacturing due to legacy tooling and engineering standards.