n. A unit of crosssectional measurement, especially of wire, equal to the area of a circle with a diameter of one mil.
http://www.answers.com/topic/circularmil

1 circular mil = 1 mil x 1 mil. a=d. 2. so if a wire has a diameter of 80 mils, it has an area of 6400 circular mils.
http://wiki.answers.com/Q/How_do_you_calculate_mil...

There are 1000 Mils to an Inch! Do you need any other conversions? ChaCha
http://www.chacha.com/question/howmanycircularm...

because mils are the tiny portion of the Imperial system and they allow whole numbers for comparison of resistance and current capacity. Also easy to calculate without Pi intruding.
http://answers.yahoo.com/question/index?qid=201207...
