kcmil, AWG, mm² & in² Converter

The most common units of measurement for cable cross-sections

1. square millimeter (mm²)

The most commonly used unit in Europe and many other countries is the square millimeter (mm²). This unit indicates the cross-sectional area of a conductor and is a direct measure of its current-carrying capacity. Typical values are:

• 0.75 mm² (small appliances and lighting)
• 1.5 mm² (socket and lighting circuits)
• 2.5 mm² (high-performance appliances such as stoves or air conditioning systems)
• 6 mm² and larger (main power lines and industrial applications)

2. American Wire Gauge (AWG)

In the USA and some other countries, the cable cross-section is measured in American Wire Gauge (AWG). AWG is based on a logarithmic scale, where a smaller number means a larger cross-section. Some examples:

• 18 AWG (equivalent to approx. 0.82 mm², often for small electrical appliances)
• 14 AWG (approx. 2.08 mm², commonly used in households for lighting)
• 10 AWG (approx. 5.26 mm², for powerful appliances)

Conversion from AWG to mm² is done using standardized tables.

3. circular mils (cmil)

This unit is mainly used in North America for very large cable cross-sections. A circular mil (cmil) is the area of a circle with a diameter of one mil (1 mil = 1/1000 inch). Cross-sections are usually specified in increments of thousands (kcmil). Typical values:

• 100 kcmil (corresponds to approx. 50.8 mm²)
• 250 kcmil (approx. 126.7 mm²)
• 500 kcmil (approx. 253.3 mm²)

4. square inch (in²)

The square inch is rarely used for electrical cables, but is used in certain industrial areas, particularly in high-voltage and energy technology. It is used to describe extremely large conductor cross-sections.

AWG Table