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.
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).