The American Wire Gauge (AWG) system is the standard for denoting wire thickness. Counter-intuitively, a higher number means a thinner wire.

Use this tool to convert AWG sizes into physical dimensions (Diameter mm, Area mm²) and estimate electrical resistance for copper conductors. Essential for determining the correct wire gauge for power loads.

Select Size

Input

AWG Size

Physical Diameter

Diameter (mm)

Diameter (inch)

Electrical Specs (Copper)

Resistance: —

Max Amps (Chassis): —

Cross-Section Area

Analysis

Area (mm²)

mm²

Area (kcmil)

kcmil

Formulas

Diameter (mm)

d_n = 0.127 × 92^(36-n)/39

Where ‘n’ is the AWG number (e.g., 0000 = -3).

Area (mm²)

A_n = (π/4) × d_n²

Cross-sectional area of the conductor.

Resistance

R ≈ (ρ × L) / A

Uses resistivity of Copper (ρ ≈ 1.68×10^-8 Ωm).

Rule of Thumb

+3 AWG ≈ 1/2 Area

Increasing gauge by 3 halves the cross-sectional area.

Common AWG Sizes & Ampacity Chart

This chart provides a quick reference for standard AWG sizes converted to millimeters, along with their maximum current carrying capacity (Ampacity) for chassis wiring.

AWG Size	Diameter (mm)	Area (mm²)	Max Amps*	Common Use
10 AWG	2.588 mm	5.26 mm²	55A	Mains Power / AC
12 AWG	2.053 mm	3.31 mm²	41A	Household Outlets
18 AWG	1.024 mm	0.82 mm²	16A	Lamps, Low Power
24 AWG	0.511 mm	0.20 mm²	3.5A	Ethernet / USB
30 AWG	0.255 mm	0.05 mm²	0.86A	Wire Wrap / PCB

* Max Amps for chassis wiring (short distance in free air). Power transmission requires lower limits.

How to Use

Select a size to see dimensions.

Select AWG Size

Use the dropdown to pick a standard AWG size. Sizes typically range from 4/0 (0000) (Thickest) to 40 (Thinnest).

Check Dimensions

Review the Diameter and Area. Use mm² for standard electrical load calculations.

Verify Capacity

Check the estimated Max Amps (Chassis Wiring) to ensure the wire can handle your current.