What is the significance of AWG in American power cables, and how can this be converted into cross-sectional area in mm²?

AWG and cross-section: Convert AWG to mm² for US power cables, device cables and data cables

Many US power cables, device cables and data cables are marked with AWG. In Europe, on the other hand, the conductor cross-section is usually specified in mm². This overview helps with quick conversion, technical classification and selection in practice.

B2B focus: purchasing, technology, product selection Relevant for US power cables, device cables and data cables Table, formula and practical examples
Rule of thumb:
The smaller the AWG number, the thicker the conductor – and the larger the cross-section.

Quickly classify AWG for cables

AWG 18
Commonly used in US power cables, physically approx. 0.82 mm²
AWG 16
More reserve in terms of power and length, physically approx. 1.31 mm²
Important in Europe
AWG values are often close to metric nominal values, but not always exactly 1:1

What does AWG mean for cables?

AWG (American Wire Gauge) is a logarithmic system commonly used in North America to indicate conductor diameter. The ratio between two consecutive AWG levels is constant. Important: AWG describes the conductor – not the insulation thickness.

Why is AWG important for product selection?

For US cables, AWG is often the decisive specification when conductor thickness, voltage drop, mechanical load capacity and the rough classification of the cross-section need to be quickly assessed.

Important note on current carrying capacity (ampacity):
The cross-section is only one factor. Permissible currents depend, among other things, on the cable type (e.g. SVT/SJT/SJTW), standard/approval (e.g. UL/CSA), ambient temperature, installation type and length. Use the values here as a guide and always check the data sheet and standard for safety-related applications.

Convert AWG to mm²: Table with common values

The following table shows common sizes as found in US power cables and many other cable types. The mm² values can be physically derived from the conductor diameter and help with quick technical orientation.

AWG Conductor diameter (mm) Cross-section (mm²) Approximate metric nominal values Typical examples
20 0.812 0.5 0.50 mm² Control and signal lines
18 1.024 0.82 0.75–1.0 mm² Many US power cables (e.g. 18/3)
17 1.150 1.04 1.0 mm² Special appliance cables
16 1.291 1.31 1.5 mm² More powerful device cables
15 1.450 1.65 1.5 mm² Industry and extensions (depending on type)
14 1.628 2.08 2.5 mm² More reserve in terms of performance and length
13 1.828 2.63 2.5 mm² Special cable, rarely used in the consumer sector
12 2.053 3.31 4.0 mm² Higher currents and longer cables

Tip: In Europe, "smooth" nominal values such as 0.75 / 1.0 / 1.5 / 2.5 / 4.0 mm² are often used – AWG is often just off.

Calculating AWG in mm²: formula for technology and data sheets

The conductor diameter of an AWG conductor can be calculated as follows:

d(mm) = 0,127 · 92^((36 − AWG) / 39)

The cross-section is then calculated as follows:

A(mm²) = π · (d/2)²

When is the formula useful in practice?

The formula is particularly helpful for technical queries, data sheets, comparative calculations and when no direct metric information is available, only an AWG designation.

Practical application: how to use AWG when selecting cables

US power cables (e.g. 18/3, 16/3)

The specification 18/3 typically means: AWG18 and 3 cores. AWG16 is often chosen for longer cables or higher loads – always depending on the cable type and approval.

LAN and patch cables (e.g. AWG26–AWG23)

For data cables, AWG often refers to the conductor in the wire pairs. Here, the focus is less on high currents and more on signal quality, attenuation and mechanical robustness.

Why is AWG not exactly the same as mm²?

AWG is a geometric conductor specification. European mm² nominal values are often rounded and standardised. Therefore, in many cases, the conversion is a very good approximation, but not always 1:1 identical.

Which AWG values are particularly common in US power cables?

In practice, AWG18 and AWG16 are particularly common. These values typically appear in US power cables, device cables and comparable connection cables.

Further information at MAG:

FAQ on AWG and cross-section

What is AWG, explained simply?

AWG is a US measurement for conductor thickness. Small number = thick conductor = larger cross-section.

What AWG values are common for US power cables?

AWG18 and AWG16 are very common, for example 18/3 or 16/3. The right choice depends on the cable type, approval and conditions of use.

Why do US cables use AWG instead of mm²?

In North America, AWG is the established standard for conductor sizes. In Europe, on the other hand, the cross-section in mm² has become the norm.

Is AWG directly comparable to mm²?

Yes, very well for technical orientation. However, European mm² values are often standardised nominal values, while AWG is derived directly from the conductor diameter.

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