Look up any American Wire Gauge from 4/0 to AWG 40 — diameter in mm and inches, cross-sectional area, copper resistance and safe ampacity — with a handy mm² to nearest-AWG converter.

mm² → nearest AWG
mm²
Enter an area in mm²
Type a metric cross-sectional area (e.g. 2.5 mm²) to find the closest American Wire Gauge and highlight it in the table below.
44 gauges
AWG Diameter (mm) Diameter (in) Area (mm²) Resistance (Ω/km) Resistance (Ω/1000 ft) Ampacity — chassis (A) Ampacity — power (A)
No gauge matches your search.
Resistance is for solid copper at 20 °C. The chassis-wiring ampacity assumes a single insulated conductor in open air; the power-transmission column is a conservative figure for conductors bundled or in conduit. Always follow your local electrical code — these are reference values only. Click any row to copy its key values; use the column headers to sort.

About Wire Gauge (AWG) Chart

This American Wire Gauge chart covers 43 gauges from 4/0 (0000, the thickest) down to AWG 40, listing each wire’s diameter in millimeters and inches, cross-sectional area in mm², copper resistance in ohms per kilometer and per 1000 feet, and typical ampacity for both chassis wiring and power transmission.

The diameters follow the standard AWG formula and the resistance figures assume copper at 20 °C, so the numbers line up with what electricians, electronics hobbyists and PCB designers expect when sizing conductors. Every column header is click-sortable, and a search box filters the table by gauge.

A built-in converter answers the most common question directly: enter a cross-section in mm² and the tool names the nearest AWG, highlighting and scrolling to the matching row. Clicking a row copies a formatted summary line for quick pasting into notes or a bill of materials.

How to use Wire Gauge (AWG) Chart

  1. Type a metric cross-section in mm² into the lookup box to get the nearest AWG — the matching row is highlighted and scrolled into view.
  2. Or search for a specific gauge (for example 12 or 4/0) to filter the table.
  3. Click any column header — diameter, area, resistance or ampacity — to sort the chart ascending or descending.
  4. Read the row for diameter in mm and inches, area, copper resistance and the chassis and power-transmission ampacity ratings.
  5. Click a row or its copy button to copy the gauge’s figures to your clipboard.

Frequently asked questions

Forty-three gauges, from 4/0 (0000) through 3/0, 2/0 and 1/0 down to AWG 40. Larger AWG numbers mean thinner wire; each step down in number roughly increases the cross-sectional area by 26%.

Enter the metric cross-section in the lookup box and the tool picks the gauge whose area is closest — for example, 2.5 mm² lands nearest AWG 13, and 4 mm² nearest AWG 11. The matched row is highlighted automatically.

Chassis wiring ratings assume short runs of wire in open air, so they are higher. Power-transmission ratings are conservative values for bundled or long runs. Always confirm against the electrical code and insulation rating that apply to your installation.

They are for solid copper conductors at 20 °C, given in ohms per kilometer and ohms per 1000 feet. Aluminum wire and higher temperatures both increase resistance, so adjust accordingly for those cases.

Yes, the full chart, sorting and the mm²-to-AWG converter are free with no registration. Everything runs in your browser, so no data is sent anywhere.

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