AWG (American Wire Gauge) is a standardized wire gauge system used in North America. Smaller AWG numbers indicate larger wire diameters. AWG 0000 (4/0) is the largest standard size, while AWG 40 is among the smallest.

How do I convert AWG to mm²?

AWG diameter in mm = 0.127 × 92^((36-AWG)/39). Area in mm² = π/4 × d². For example, AWG 10 = 5.26 mm², AWG 14 = 2.08 mm², AWG 18 = 0.823 mm².

What is the difference between AWG and SWG?

AWG (American Wire Gauge) is used in North America, while SWG (Standard Wire Gauge, also called Imperial Wire Gauge) is used in the UK. The same gauge number gives different diameters in each system.

What wire gauge do I need?

Wire gauge depends on current: AWG 14 (2.08 mm²) for up to 15A, AWG 12 (3.31 mm²) for 20A, AWG 10 (5.26 mm²) for 30A, AWG 8 (8.37 mm²) for 40A. Always check local electrical codes.

Does wire gauge affect resistance?

Yes. Smaller gauge (larger number) = thinner wire = higher resistance. Resistance is inversely proportional to cross-sectional area. Copper resistivity at 20°C is 1.724×10⁻⁸ Ω·m.

Free Engineering Tool

Wire Gauge Converter

Convert between AWG, mm², and SWG wire gauges. Look up diameter, cross-section area, and DC resistance for copper conductors.

AWGmm²SWGCopper

Input Mode

AWG Gauge

Common sizes

Conversion Results

Cross-Section Area

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Diameter

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AWG (nearest)

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DC Resistance (Cu, 20°C)

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Nearest SWG

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AWG	⌀ mm	mm²	Ω/m (Cu)	Max A (approx)

Wire Gauge Converter | AWG ↔ mm² ↔ SWG | Free Online Tool

Published by Nikolai Shelkovenko on February 15, 2026 February 15, 2026

Conversion Results