Wire Gauge Converter

Convert between AWG (American Wire Gauge) and metric wire sizes. View diameter, area, and resistance.

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1. Select your input type - either AWG gauge number or metric diameter in millimeters. 2. Enter the wire gauge number or metric size you want to convert. 3. View the converted values including diameter (mm), cross-sectional area (sq mm), and resistance per meter. 4. Browse the full reference table showing all standard AWG gauges with their metric equivalents. 5. Use the resistance-per-length figures to calculate voltage drop for your specific wire run distance.

About This Tool

The American Wire Gauge (AWG) system is widely used in North America to describe wire sizes, but most of the world uses metric measurements in millimeters. This converter bridges the gap, letting you instantly translate between AWG numbers and metric dimensions including diameter in millimeters, cross-sectional area in square millimeters, and resistance per unit length.

The tool covers the full range of standard wire gauges from 0000 (4/0) through 40 AWG, which spans everything from heavy power cables to fine magnet wire. Each gauge listing includes the diameter, cross-sectional area, and typical resistance in ohms per meter and ohms per 1000 feet.

Whether you are wiring a building, selecting cable for an audio system, choosing wire for a robotics project, or sourcing materials from international suppliers, this converter ensures you pick the right wire size regardless of which measurement system the specifications use.

Formula / How It Works

Diameter (mm) = 0.127 x 92^((36 - AWG) / 39) | Area (mm^2) = pi / 4 x d^2 | Resistance = resistivity x length / area

Frequently Asked Questions

AWG is a standardized wire gauge system used primarily in North America. The gauge number is inversely related to wire diameter - a smaller AWG number means a thicker wire. AWG 0000 (4/0) is about 11.7 mm in diameter, while AWG 40 is only about 0.08 mm. Each decrease of 6 gauge numbers roughly doubles the wire diameter.
The formula for converting AWG to diameter in millimeters is: d(mm) = 0.127 x 92^((36 - AWG) / 39). For common sizes, 12 AWG is about 2.05 mm, 14 AWG is about 1.63 mm, and 18 AWG is about 1.02 mm in diameter. This calculator handles the conversion automatically.
In the US, 14 AWG (2.08 sq mm) is standard for 15-amp circuits and 12 AWG (3.31 sq mm) for 20-amp circuits. Kitchen, bathroom, and garage outlets typically require 20-amp circuits. Always consult local electrical codes and a licensed electrician for specific installations.
Solid wire is a single conductor, while stranded wire consists of multiple thinner wires twisted together. Both can have the same AWG rating (based on total cross-sectional area), but stranded wire is more flexible and resistant to metal fatigue from vibration. Solid wire is easier to terminate and slightly better for long straight runs.
The AWG number defines only the physical dimensions (diameter and area) - not the material. However, different materials have different resistivity. Copper is the most common conductor and the reference standard. Aluminum wire of the same gauge has about 61% the conductivity of copper, so a larger gauge aluminum wire is needed to carry the same current.

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