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.
An "are" (symbol: a) is a unit of area that is not part of the International System of Units (SI) but is used in some countries, particularly in Europe, for measuring land areas. One are is equal to 100 square meters (m²).
To put it simply, 1 are is equivalent to a square with sides that each measure 10 meters. It is a relatively convenient unit for measuring smaller land areas, such as gardens, small fields, or land plots, where using square meters might result in large numbers.
Here are some additional conversions to provide context:
For example, if you have a piece of land that is 5 ares in size, it would be equivalent to 500 square meters (5 ares * 100 m²/are = 500 m²).