🔌 Electrical
AWG to mm² Converter
Pick an AWG size or a cross-section and press Convert. AWG numbers run backwards: a lower number is a thicker wire.
About the AWG to mm² Converter
Converting AWG to mm2 is not a linear step. AWG is a logarithmic standard, so each step of three roughly halves the cross-sectional area. That is why 12 AWG (3.31 mm²) and 14 AWG (2.08 mm²) are a step apart and 10 AWG (5.26 mm²) is double the 12.
Metric cable is sold by cross-section, so an imperial drawing and a European cable schedule do not match exactly: 12 AWG is 3.31 mm², which is nearer to 2.5 mm² or 4 mm² than to a metric size of its own. For anything carrying current, use the ampacity table for the cable you actually have.
How the calculation works
- Area (mm²) = 0.012668 × 92^((36 − AWG) ÷ 19.5)
- Diameter (mm) = 0.127 × 92^((36 − AWG) ÷ 39)
- 12 AWG = 3.31 mm² · 14 AWG = 2.08 mm² · 16 AWG = 1.31 mm²
Reference values
| AWG | mm² | Typical use |
|---|---|---|
| 6 AWG | 13.30 mm² | Service entrance |
| 8 AWG | 8.37 mm² | Range, sub-panel |
| 10 AWG | 5.26 mm² | Dryer, 30 A |
| 12 AWG | 3.31 mm² | 20 A circuits |
| 14 AWG | 2.08 mm² | 15 A lighting |
| 16 AWG | 1.31 mm² | Extension leads |
| 18 AWG | 0.823 mm² | Lamp cord |
| 22 AWG | 0.326 mm² | Electronics |
Worked examples
- 10 AWG is 5.26 mm², the usual size for a 30 A dryer circuit.
- 18 AWG is 0.823 mm², typical lamp cord.
- 6 AWG is 13.30 mm², a service-entrance conductor.
Matching metric cable
Metric cable is sold in 1.5, 2.5, 4 and 6 mm², which do not line up with AWG. 12 AWG at 3.31 mm² sits between 2.5 and 4 mm², so neither substitute is a like-for-like replacement. Match the cross-section upward and re-check the ampacity for the installation method.
Common mistakes
- Reading AWG as a diameter in millimetres. It is a gauge number; 12 AWG is 2.05 mm across, not 12 mm.
- Replacing 2.5 mm² with 14 AWG, which is 2.08 mm² and slightly smaller.
- Ignoring that ampacity also depends on insulation, bundling and ambient temperature.
A last check on the numbers: 37 AWG 12 works out to 122.5 Square millimetre, and reversing that with the same factor brings you back to 37 AWG 12. Because AWG 12 to Square millimetre is a single multiplication, any tool that gives a different figure for the same input is rounding somewhere in the middle rather than only at the end.