How is AWG converted to mm2?

Wire diameter in mm is calculated as 0.127 x 92^((36-n)/39), where n is the AWG number. The cross-sectional area in mm2 is then pi/4 times the diameter squared.

What do 1/0, 2/0, 3/0, and 4/0 mean?

These are gauges larger than AWG 1, sometimes called "aught" sizes. In the formula, 1/0 equals n=0, 2/0 equals n=-1, 3/0 equals n=-2, and 4/0 equals n=-3. Larger number of zeros means a thicker wire.

Why do published AWG-to-mm2 charts vary slightly?

The AWG standard defines wire by diameter, so mm2 area is a derived, rounded value. Different manufacturers round to 2 or 3 significant figures, which produces small differences between charts.

Does this account for stranded wire?

No. This tool calculates the theoretical solid-conductor area from the AWG formula. Stranded wire of the same AWG rating has the same nominal copper cross-section but a larger overall bundle diameter due to gaps between strands.

What AWG is closest to 2.5 mm2 or 1.5 mm2 wire?

2.5 mm2 is closest to AWG 14 (2.08 mm2), and 1.5 mm2 is closest to AWG 16 (1.31 mm2). Neither is an exact match since AWG and metric wire standards use different size steps.

AWG to mm2 Converter

Name: AWG to mm2 Converter
Availability: InStock
Author: Nham Vu

Pick an AWG size to get its cross-sectional area in mm2, diameter in mm, and a full reference table.

Wire Gauge

AWG Size

Custom AWG Number (optional, overrides dropdown)

Use -3, -2, -1, 0 for 4/0, 3/0, 2/0, 1/0.

Conversion Result

Area

mm2

Diameter

inch

Wire gauge: 10 AWG
Nearest metric size: --
Circular mils: --

AWG to mm2 Reference Table

Common gauges, 4/0 through 40 AWG.

AWG	Diameter (mm)	Area (mm2)

Summary

Pick an AWG size to get its cross-sectional area in mm2, diameter in mm, and a full reference table.

How it works

Select an AWG wire size from the dropdown, or type a custom gauge number.
Read the cross-sectional area in square millimeters.
Check the diameter in millimeters and inches for the same gauge.
Scroll the reference table to compare nearby gauges at a glance.

Use cases

Match a US AWG wire spec to metric mm2 cable ratings.
Convert an imported wiring diagram that lists AWG sizes to metric documentation.
Cross-check a metric cable gland or lug against the AWG wire it needs to fit.
Compare adjacent gauge sizes when substituting wire during a repair.

Frequently Asked Questions

Last updated: 2026-07-21 · Reviewed by Nham Vu