Electrical wire size converter

AWG to mm² Converter

Convert American wire gauge to square millimeters, conductor diameter, circular mils, and estimated resistance. Useful for comparing US wire sizes with metric cable sizes.

Convert wire gauge or conductor area

Enter an AWG size or a metric conductor area. Results update instantly with the nearest common size.

Nearest wire size 12 AWG ≈ 3.31 mm² Common branch-circuit comparison size.
Diameter 2.05 mm
Resistance estimate 5.21 Ω/km
12 AWG has about 3.31 mm² of conductor area and a bare diameter near 2.05 mm.

How to use this AWG converter

  1. Choose AWG, mm², or bare conductor diameter.
  2. Enter the value you know, such as 14 AWG or 2.5 mm².
  3. Compare the nearest AWG size, metric area, diameter, and resistance estimate.
  4. Use the result as a sizing reference, then confirm code, temperature, insulation, and manufacturer ratings for real installations.

Common AWG to mm² chart

AWGAreaDiameterCopper Ω/km

AWG to mm² conversion FAQ

What does AWG mean?

AWG means American Wire Gauge. Smaller AWG numbers are larger conductors, so 10 AWG is bigger than 18 AWG.

What is 14 AWG in square millimeters?

14 AWG is about 2.08 mm², with a bare conductor diameter of about 1.63 mm.

Can I use the nearest mm² size for electrical work?

Use the converter for comparison, shopping, and planning. For installed wiring, follow the applicable electrical code and check ampacity, insulation temperature, conduit fill, voltage drop, and the product datasheet.