18 AWG to mm² – Wire Size & Diameter
18 AWG = 0.823 mm²
18 AWG solid wire has a cross-section of 0.823 mm² and a diameter of 1.024 mm (0.0403 in).
Step by step
- Diameter: d = 0.127 × 92^((36 − 18)/39) = 1.0237 mm.
- Area: π/4 × d² = 0.823 mm².
18 AWG is a thin gauge for electronics, speakers and low-voltage signals.
Details
- Area
- 0.823 mm²
- Diameter
- 1.024 mm (0.0403 in)
- Area in kcmil
- 1.62
- Nearest metric size
- 0.75 mm²
- Copper resistance
- 20.947 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 18 AWG in mm²?
0.823 mm².
What is the diameter of 18 AWG wire?
1.024 mm (solid conductor).
What metric wire replaces 18 AWG?
Use the next metric size up with at least 0.82 mm².
Is stranded wire the same size?
Stranded wire of the same gauge has the same copper area but a slightly larger overall diameter.