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.
A square mil (abbreviated as sq mil or mil²) is a unit of area measurement used primarily in the United States for very small areas, especially in the context of electrical engineering and wire gauge measurements. One square mil is equal to one square thousandth of an inch or one square mil (0.000001 square inches).
In terms of modern metric units, one square mil is approximately equal to 6.4516 square micrometers (µm²) because there are 25.4 micrometers in one thousandth of an inch (1 mil).
Square mils are often used when specifying the cross-sectional area of wires, particularly in electrical and electronic engineering. For example, the American Wire Gauge (AWG) system uses square mils to represent the cross-sectional area of wires, with smaller wire sizes having fewer square mils, and larger wire sizes having more square mils.