How is mm2 converted to AWG?

The wire diameter is derived from the area (d = sqrt(4 x area / pi)), then the AWG number is calculated as n = 36 - 39 x log(d / 0.127) / log(92). The result is rounded to the nearest standard gauge.

Why is the result a rounded gauge instead of an exact match?

AWG sizes are a fixed geometric sequence of diameters, so most metric areas fall between two standard gauges. This tool shows both the exact (fractional) gauge and the nearest standard size.

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

By cross-sectional area, 2.5 mm2 rounds to AWG 13 (2.62 mm2) and 1.5 mm2 rounds to AWG 15 (1.65 mm2). Cable tables often pair 2.5 mm2 with 14 AWG and 1.5 mm2 with 16 AWG instead, since those pairings are chosen for ampacity headroom rather than a strict area match.

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

These are gauges larger than AWG 1, sometimes called "aught" sizes. Larger number of zeros means a thicker wire, with 4/0 being the largest size in the standard table.

Does this account for stranded wire?

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

mm2 to AWG Converter

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

Enter a wire area in mm2 to get the nearest standard AWG size, exact gauge, and diameter.

Wire Area

Common mm2 Sizes

Custom Area (mm2) (optional, overrides dropdown)

Enter the cross-sectional area in square millimeters.

Conversion Result

Nearest AWG

standard gauge

Diameter

inch

Input area: 2.5 mm2
Exact gauge (unrounded): --
Circular mils: --

mm2 to AWG Reference Table

Common gauges, 4/0 through 40 AWG.

AWG	Area (mm2)	Diameter (mm)

Summary

Enter a wire area in mm2 to get the nearest standard AWG size, exact gauge, and diameter.

How it works

Enter the wire cross-sectional area in square millimeters.
Read the nearest standard AWG size and the exact (non-rounded) gauge.
Check the diameter in millimeters and inches for the same wire.
Scroll the reference table to compare nearby gauges at a glance.

Use cases

Match a metric mm2 cable spec to the closest US AWG wire size.
Convert an imported wiring diagram that lists mm2 to AWG for US documentation.
Check which AWG terminal or lug fits a given metric wire area.
Compare adjacent gauge sizes when substituting wire during a repair.

Frequently Asked Questions

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