mm2 to awg calculator

Why convert mm² to AWG?

Electrical projects often mix international standards. Many European and Asian cables are labeled in square millimeters (mm²), while U.S.-based components and connectors are typically specified in AWG. This calculator helps you quickly translate between both systems so you can choose matching wire, terminals, ferrules, and breakers.

The conversion is based on conductor cross-sectional area and standard AWG geometry. It is useful for panel wiring, automotive work, battery cables, solar installations, low-voltage control systems, and general electronics.

How the conversion works

1) mm² to AWG

We first convert area to diameter, then use the AWG logarithmic relationship:

• d(mm) = √(4A/π)
• AWG = 36 − 39 × log(d/0.127) / log(92)

The result can be fractional (for example, AWG 13.6). The calculator also shows the nearest standard AWG size.

2) AWG to mm²

For a selected AWG number, we compute diameter and area:

• d(mm) = 0.127 × 92^((36−AWG)/39)
• A(mm²) = π × d² / 4

Quick reference table

AWG	Approx. Area (mm²)	Common Use
20	0.52	Signal/control wiring
18	0.82	Low-current circuits, sensors
16	1.31	Light power wiring
14	2.08	Branch circuits (regional code dependent)
12	3.31	Higher current branch circuits
10	5.26	Appliances, feeders
8	8.37	Heavier loads, battery runs
4	21.15	Inverters, starter wiring
1/0	53.48	High-current battery cable
4/0	107.22	Very high current feeds

Practical tips

• Always verify ampacity by code (NEC/IEC/local rules), not by size conversion alone.
• Insulation temperature rating changes current capacity significantly.
• Stranded vs. solid can affect terminal fit and real copper fill.
• Voltage drop matters for long runs—sometimes you should upsize beyond minimum ampacity.
• Use matched lugs/ferrules rated for the exact conductor class and size.

FAQ

Is this conversion exact?

It is mathematically exact for standard AWG geometry. In real products, manufacturing tolerances and strand construction can slightly change measured area.

Why does mm² to AWG return a decimal AWG?

Because mm² values are continuous while AWG is a fixed gauge series. Decimal AWG indicates a point between two standard wire sizes.

Can I use this for aluminum wire too?

Yes for geometric size conversion. But ampacity and resistance differ by material, so always apply aluminum-specific electrical design rules.

Bottom line

If you're comparing international wire specs, this mm² to AWG calculator gives you a fast and reliable translation. Use it as a sizing bridge, then confirm final conductor choice with code-compliant ampacity, temperature, installation method, and voltage drop calculations.