Wire Size Converter - AWG mm² kcmil Conversion Chart | Free Online

Input Unit

AWG Value

e.g., 12, 4/0 (0000)

Conversion Result

AWG

Cross-sectional Area

3.309mm²

kcmil (MCM)

6.53

Diameter

2.053mm

Diameter

0.0808inch

Resistance (20°C)

5.211Ω/km

Max Current (Reference)

~20A

Wire Cross-section Comparison

122.05 mm

AWG 122.05 mm

AWG 102.59 mm

AWG 83.26 mm

AWG 64.12 mm

AWG Guide

What is AWG?

American Wire Gauge. Smaller numbers mean thicker wires. Wires thicker than 0 are denoted as 2/0, 3/0, 4/0.

Area Formula

AWG area (kcmil) = 1000 × (diameter in mils)². 1 kcmil = 0.5067 mm²

What is the Wire Size Converter?

A tool that converts between wire gauge units including AWG (American Wire Gauge), mm² (square millimeter), and kcmil (MCM). Provides comprehensive information about wire specifications including cross-sectional area, diameter, resistance, and ampacity.

Conversion among AWG, mm², and kcmil
Simultaneous cross-sectional area and diameter (mm/inch) display
Reference resistance values for copper wire at 20°C
Reference ampacity display
Visual comparison of wire cross-section sizes
Quick selection of common sizes

How to Use

1
Choose an Input Unit
Choose the known wire-size unit: AWG, mm², or kcmil.
2
Enter a Value
Enter a value in the selected unit. AWG supports formats such as 12 and 4/0 (0000).
3
Review the Results
View the converted values along with diameter, resistance, and ampacity information.
4
View the Visualization
Compare the actual sizes of wire cross sections visually.

Frequently Asked Questions

Yes. The smaller the AWG number, the thicker the wire. AWG 4 is much thicker than AWG 12. Sizes thicker than 0 are written as 2/0, 3/0, and 4/0.

Korea primarily uses mm² (square millimeters). For example, household wiring is commonly 2.5mm² or 4mm².

U.S. products and data sheets use AWG, while Korean and European standards use mm², so conversion is necessary to check compatibility.

kcmil is a unit for large wires, typically AWG 4/0 and above. 1 kcmil = 1000 circular mil, and the unit is used in electrical power distribution.

Actual ampacity varies with conductor material, insulation type, installation conditions (concealed or exposed), ambient temperature, and other factors, so it is provided only as a reference.

Tips & Best Practices

Household outlet wiring typically uses 2.5mm² (AWG 14), while a dedicated air-conditioner circuit uses 4mm² (AWG 12).
AWG 4/0 (0000) is about 107mm² and is used for residential service-entrance cables or large-motor wiring.
When buying a U.S. product, convert its AWG size to mm² to check compatibility with locally available wire.
Wire resistance increases with length, so consider using the next thicker size for long cable runs.
Use the visualization to compare wire cross-section sizes at a glance.

What is the Wire Size Converter?

Conversion among AWG, mm², and kcmil

Simultaneous cross-sectional area and diameter (mm/inch) display

Reference resistance values for copper wire at 20°C

Reference ampacity display

Visual comparison of wire cross-section sizes

Quick selection of common sizes

How to Use

Choose an Input Unit

Choose the known wire-size unit: AWG, mm², or kcmil.

Enter a Value

Enter a value in the selected unit. AWG supports formats such as 12 and 4/0 (0000).

Review the Results

View the converted values along with diameter, resistance, and ampacity information.

View the Visualization

Compare the actual sizes of wire cross sections visually.

Frequently Asked Questions

Yes. The smaller the AWG number, the thicker the wire. AWG 4 is much thicker than AWG 12. Sizes thicker than 0 are written as 2/0, 3/0, and 4/0.

Korea primarily uses mm² (square millimeters). For example, household wiring is commonly 2.5mm² or 4mm².

U.S. products and data sheets use AWG, while Korean and European standards use mm², so conversion is necessary to check compatibility.

kcmil is a unit for large wires, typically AWG 4/0 and above. 1 kcmil = 1000 circular mil, and the unit is used in electrical power distribution.

Actual ampacity varies with conductor material, insulation type, installation conditions (concealed or exposed), ambient temperature, and other factors, so it is provided only as a reference.

Tips & Best Practices

Household outlet wiring typically uses 2.5mm² (AWG 14), while a dedicated air-conditioner circuit uses 4mm² (AWG 12).

AWG 4/0 (0000) is about 107mm² and is used for residential service-entrance cables or large-motor wiring.

When buying a U.S. product, convert its AWG size to mm² to check compatibility with locally available wire.

Wire resistance increases with length, so consider using the next thicker size for long cable runs.

Use the visualization to compare wire cross-section sizes at a glance.