UOM Converter

Wire size and conduit converters

AWG / kcmil → mm²

North American wire size to metric area and the matching IEC 60228 size.

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Convert from

More optionsCopper
Metal (for weight)

12 AWG equals

Cross-sections to scale: 12 AWG (3.31 mm²), 4 mm² (nearest)12 AWG3.31 mm²4 mm²nearest

Metric wire size (IEC)

Area

Weight, bare copper

How it's calculated
  • AWG diameter = 0.127 mm × 92^((36 − gauge) ÷ 39), the ASTM B258 definition. 1/0 is gauge 0, 4/0 is gauge −3.
  • 1 kcmil = 1,000 circular mils = 0.5067 mm².
  • Weight = area × density: copper 8.89 g/cm³, aluminum 2.705 g/cm³. Bare solid metal; stranding adds about 2%, insulation not included.

Worked examples

12 AWG equals

  • Cross-section: 3.309 mm²
  • Nearest size: 4 mm²
  • Smallest size at least as big: 4 mm²
  • Thousand circular mils: 6.53 kcmil
  • Diameter, solid conductor: 2.053 mm

4/0 AWG equals

  • Cross-section: 107.219 mm²
  • Nearest size: 120 mm²
  • Smallest size at least as big: 120 mm²
  • Thousand circular mils: 211.6 kcmil
  • Diameter, solid conductor: 11.684 mm

250 kcmil equals

  • Cross-section: 126.677 mm²
  • Nearest size: 120 mm²
  • Smallest size at least as big: 150 mm²
  • Thousand circular mils: 250 kcmil
  • Pounds per 1,000 ft: 756.7 lb

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