A circular mil (often abbreviated as cmil or kcmil) is a unit of area used primarily in the United States for measuring the cross-sectional area of a round wire or cable. It is a convenient unit for specifying the size of electrical conductors.
One circular mil is equal to the area of a circle with a diameter of one mil (1/1000th of an inch) or approximately 0.000000506707 square inches (in²). In metric units, one circular mil is approximately equal to 0.000001273 square millimeters (mm²).
Circular mils are commonly used in the American Wire Gauge (AWG) system to specify wire sizes. The AWG system assigns a unique number to each wire size, and this number is related to the wire's cross-sectional area in circular mils. For example, a larger AWG number corresponds to a smaller wire size with fewer circular mils, while a smaller AWG number corresponds to a larger wire size with more circular mils. This system allows for easy reference and selection of wire sizes for various electrical applications.
A square centimeter (often abbreviated as cm²) is a unit of area in the International System of Units (SI). It represents a square with sides that each measure 1 centimeter (cm) in length.
One square centimeter is equal to 0.0001 square meters (m²) because there are 100 centimeters in a meter, and when you square that length, you get 0.01 square meters.
To visualize the size of a square centimeter, you can imagine a tiny square with sides that are each 1 centimeter long. It is a small unit of area and is often used for measurements of small objects or details, especially in scientific and engineering contexts.