12 AWG to mm² – Wire Size & Diameter
12 AWG = 3.309 mm²
12 AWG solid wire has a cross-section of 3.309 mm² and a diameter of 2.053 mm (0.0808 in).
Step by step
- Diameter: d = 0.127 × 92^((36 − 12)/39) = 2.0525 mm.
- Area: π/4 × d² = 3.3088 mm².
12 AWG copper is the standard for 20 A kitchen, bathroom and garage circuits.
Details
- Area
- 3.309 mm²
- Diameter
- 2.053 mm (0.0808 in)
- Area in kcmil
- 6.53
- Nearest metric size
- 4 mm²
- Copper resistance
- 5.21 Ω/km
How it works
The American Wire Gauge system is logarithmic: smaller numbers mean thicker wire, every 6 gauges halve the diameter and every 3 gauges roughly halve the area. Metric wire is specified directly by cross-sectional area in mm², so the sizes never line up exactly. When substituting, choose a conductor with at least the same area, and always follow local electrical codes.
Nearby values
Related conversions
Frequently asked questions
What is 12 AWG in mm²?
3.309 mm².
What is the diameter of 12 AWG wire?
2.053 mm (solid conductor).
What metric wire replaces 12 AWG?
Use the next metric size up with at least 3.31 mm².
Is stranded wire the same size?
Stranded wire of the same gauge has the same copper area but a slightly larger overall diameter.