1. What Are Circular Mils?

Circular mils (CM) is a unit of area used primarily in the United States for referring to the cross-sectional area of a wire or cable. One circular mil is the area of a circle with a diameter of one mil (one thousandth of an inch).

2. How Does The Calculator Work?

The calculator uses the circular mils formula:

Where:

• \( Diameter \) — Wire diameter in mils (1 mil = 0.001 inch)

Explanation: The formula calculates the cross-sectional area of a wire by squaring its diameter in mils.

3. Importance of Circular Mils Calculation

Details: Calculating circular mils is essential for electrical engineers and technicians to determine wire size, current carrying capacity, and voltage drop in electrical systems.

4. Using The Calculator

Tips: Enter the wire diameter in mils. The value must be greater than zero. The calculator will automatically compute the circular mils area.

5. Frequently Asked Questions (FAQ)

Q1: What is the difference between circular mils and square mils?
A: Circular mils is specifically for circular cross-sections, while square mils is for square areas. 1 circular mil = π/4 square mils ≈ 0.7854 square mils.

Q2: Why use circular mils instead of square inches?
A: Circular mils provide a more convenient unit for wire measurements since wire diameters are typically small and measured in mils or inches.

Q3: How do I convert circular mils to square millimeters?
A: Multiply circular mils by 0.0005067 to get square millimeters (1 CM = 0.0005067 mm²).

Q4: What is the relationship between circular mils and American Wire Gauge (AWG)?
A: AWG sizes correspond to specific circular mil areas. As AWG number decreases, the circular mil area increases.

Q5: Can this calculator be used for rectangular conductors?
A: No, this calculator is specifically for circular cross-sections. For rectangular conductors, use square mils or square millimeters.