with square inches rather than square mils, the definition of a mil in inches can be substituted: Square millimetres Likewise, since 1 inch is defined as exactly 25.4mm, 1mil is equal to exactly 0.0254mm, so a similar conversion is possible from circular mils to square millimetres: Example calculations A 0000 AWG solid wire is defined to have a diameter of exactly . The cross-sectional area of this wire is: Formula 1: circular mil Note: 1 inch = 1000 mils (This is the same result as the AWG circular mil formula shown below for n = −3) Formula 2: square mil Formula 3: square inch Calculating diameter from area When large diameter wire sizes are specified in kcmil, such as the widely used 250 kcmil and 350 kcmil wires, the diameter of the wire can be calculated from the area without using : Note: We first convert from kcmil to circular mil Thus, this wire would have a diameter of a half inch or 12.7 mm. Metric equivalent Some tables give conversions to circular millimetres (cmm). The area in cmm is defined as the square of the wire diameter in mm. However, this unit is rarely used in practice. One of the few examples is in a patent for a bariatric weight loss device. AWG circular mil formula The formula to calculate the circular mil for any given AWG (American Wire Gauge) size is as follows. represents the circular mil area for the AWG size . For example, a number 12 gauge wire would use : Sizes with multiple zeros are successively larger than 0AWG and can be denoted using "number of zeros/0"; for example "4/0" for 0000AWG. For an /0AWG wire, use in the above formula. For example, 0000AWG (4/0AWG), would use ; and the calculated result would be 211,600 circular mils. Standard sizes Standard sizes are from 250 to 400 in increments of 50kcmil, 400 to 1000 in increments of 100kcmil, and from 1000 to 2000 in increments of 250kcmil. The diameter in the table below is that of a solid rod with the given conductor area in circular mils. Stranded wire is around 5% larger in diameter to allow for gaps between the strands, depending on the number and size of strands. Note: For smaller wires, consult . See also Thou (length) Square mil IEC 60228, the metric wire-size standard used in most parts of the world. American