Square mil

Square mil is a unit of measurement equal to the area of a square with sides of length one mil, one thousandth of an inch. This unit of area is usually used in specifying the area of the cross section of a wire or cable. The area in square mils A of a circle is given by:

$A=pi*r^{2}=pi/4*d^{2}$

where r and d are the radius and diameter, respectively, in mils.

1 square mil =
1 millionth of a square inch
6.4516e-10 $m^{2}$
$4/pi$ circular mils = .7854 square mils

See also:
square mil