Copper wire data
| Diameter | Cross section area | Resistance at 20°C | AWG (or closest) | Solid wire skin effect start frequency | Weight | Circular mils (CM) | Recommended max current in a tight coil (700 CM/A) | Recommended max current for house wiring (300 CM/A) |
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The area is calculated with the formula π*r2, where r is the radius (= diameter/2).
The resistance is calculated as 1/(58.108 * area). The area is in mm2 and the result is Ω/meter. This is the standard formula for 100% IACS pure annealed copper.
Skin effect depth is approximated with the formula 0.066/√f, with frequency in Hz and the result in meters.
The start frequency presented here is the frequency when the skin effect is same as the radius. fs = (66 / r)2, where r is the radius in mm.
Weight is calculated from the volume of 1 meter cable times the density of copper, 8.96 g/cm3. Gram per meter cable = 8.96 * area, with area in mm2
Circular mil (CM) is a North American unit of area and equal to the area of a circle with the diameter of one mil, with one mil being a thousandth of an inch. One CM is approximately 5.067·10-4 mm2.