A square mil is a

unit Unit may refer to: Arts and entertainment * UNIT, a fictional military organization in the science fiction television series ''Doctor Who'' * Unit of action, a discrete piece of action (or beat) in a theatrical presentation Music * ''Unit'' (a ...

area Area is the quantity that expresses the extent of a region on the plane or on a curved surface. The area of a plane region or ''plane area'' refers to the area of a shape or planar lamina, while ''surface area'' refers to the area of an open su ...

, equal to the area of a square with sides of length one mil. A mil is one thousandth of an international

inch Measuring tape with inches The inch (symbol: in or ″) is a unit of length in the British imperial and the United States customary systems of measurement. It is equal to yard or of a foot. Derived from the Roman uncia ("twelft ...

. This unit of area is usually used in specifying the area of the cross section of a wire or cable.

Equivalence to other units of area

1 square mil is equal to: * 1 millionth of a square inch (1 square inch is equal to 1 million square mils) * 6.4516×10⁻¹⁰ square

metre The metre ( British spelling) or meter ( American spelling; see spelling differences) (from the French unit , from the Greek noun , "measure"), symbol m, is the primary unit of length in the International System of Units (SI), though its p ...

s * about 1.273

circular mil A circular mil is a unit of area, equal to the area of a circle with a diameter of one mil (one thousandth of an inch or ). It corresponds to approximately . It is a unit intended for referring to the area of a wire with a circular cross section. ...

s (1 circular mil is equal to about 0.7854 square mils). Where 1.273 is (1÷(π÷4)) and where 0.7854 is (π÷4).

Equivalence to other units of area

See also