What is AWG and why does it matter?

American Wire Gauge (AWG) is a standardized system for wire diameter. Smaller AWG numbers mean thicker wire. Diameter and cross-sectional area determine current capacity, voltage drop, and mechanical strength, so accurate conversion is essential for selecting safe conductors.

How do I convert AWG to millimeters?

Use the AWG diameter formula: diameter (in) = 0.005 × 92^((36 - AWG)/39), then convert inches to millimeters (× 25.4). Example: 12 AWG ≈ 0.0808 in = 2.05 mm diameter.

What is the difference between diameter and cross-sectional area?

Diameter is a single dimension, while cross-sectional area determines how much current the wire can carry. Area is computed as A = π × (d/2)^2. For example, 12 AWG has about 3.31 mm² area even though the diameter is only 2.05 mm.

Why do AWG numbers look reversed?

AWG is logarithmic and historically based on the number of drawing steps. Each gauge step changes diameter by a constant ratio (92^(1/39)). Every 3 AWG steps roughly doubles or halves the cross-sectional area.

Does AWG apply to stranded wire too?

Yes. AWG describes total conductor cross-sectional area, regardless of whether it is solid or stranded. Stranded conductors have slightly larger overall diameter due to air gaps, but the conductive area is equivalent.

What AWG sizes match common metric cables?

Common equivalences: 14 AWG ≈ 2.08 mm², 12 AWG ≈ 3.31 mm², 10 AWG ≈ 5.26 mm², 8 AWG ≈ 8.37 mm². Exact diameters vary slightly by standard, so use the calculator for precision.

AWG to MM Converter

ASTM B258NEC 2023IEC 60228

ASTM B258NEC 2023

Wire Size Conversion

Select an AWG wire size to convert to metric units with electrical properties.

Frequently Asked Questions

Common questions about this calculator

AWG to MM Converter

Frequently Asked Questions

01What is AWG and why does it matter?

02How do I convert AWG to millimeters?

03What is the difference between diameter and cross-sectional area?

04Why do AWG numbers look reversed?

05Does AWG apply to stranded wire too?

06What AWG sizes match common metric cables?