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

AWG, mm² and conductor cross-sectional area

AWG and cross-sectional area: converting AWG to mm² and classifying correctly

Many US power cables, appliance leads and data cables are labelled with AWG. In Europe, however, the conductor cross-section is usually specified in mm². This page provides assistance with conversion, technical classification and practical selection for procurement, engineering and project planning.

B2B focus: Procurement & Engineering – US power cables, appliance leads, data cables: table, formula and practical examples
AWG 18
 
approx. 0.82 mm²
AWG 16
 
approx. 1.31 mm²
AWG 14
 
approx. 2.08 mm²
Rule of thumb: The smaller the AWG number, the thicker the conductor and the larger the cross-sectional area.

Understanding AWG

AWG is a North American sizing system for conductors. Important: A smaller AWG number means a thicker conductor.

Correctly interpreting mm²

The conversion is useful for European data sheets, tenders and technical comparisons. However, AWG and metric nominal values are not always exactly equivalent on a 1:1 basis.

Check current-carrying capacity separately

The cross-sectional area is only one factor. Permissible currents always depend on the cable type, connector, certification, temperature and application.

What does AWG mean for cables?

AWG stands for American Wire Gauge. The system describes conductor size and is used primarily in North America. It is based on a logarithmic scale: between two AWG grades, the diameter and cross-sectional area change in fixed ratios.

Important for practical use

  • A smaller number = a thicker conductor: AWG 16 is thicker than AWG 18.
  • AWG describes the conductor: it does not automatically refer to the sheath, insulation thickness or outer diameter.
  • Current-carrying capacity is not determined by AWG alone: cable type and certification remain crucial.

Practical tip: On US power cables, you’ll often see specifications such as 18/3 or 16/3. This typically means AWG 18 or AWG 16 with 3 conductors.

Which AWG values are commonly used in everyday B2B practice?

AWG 18: physically approx. 0.82 mm², common in US appliance leads
AWG 16 (physical cross-sectional area approx. 1.31 mm²), offering greater headroom in terms of length and power
AWG 14 (physically approx. 2.08 mm²), for higher requirements depending on cable type

Note: These values are for technical classification purposes only. For safety-critical applications, the data sheet, labelling, certification and specific operating conditions are decisive.

Converting AWG to mm²: Table of common values

The table shows common AWG sizes for mains cables, appliance cables and data cables. The mm² values are calculated approximations based on the conductor diameter and aid in rapid technical pre-selection.

AWG Conductor Ø approx. mm Cross-sectional area approx. mm² Approximate metric equivalent Typical examples
26 0.405 0.13 Fine data/signal cable Patch cables, data cables depending on the configuration
24 0.511 0.20 fine data/signal wire Network and data cables, depending on category
23 0.573 0.26 Fine data/signal conductor Installation/data cables, depending on construction
20 0.812 0.52 close to 0.50 mm² Control, signal and smaller equipment cables
18 1.024 0.82 between 0.75 and 1.0 mm² Many US power cables, e.g. 18/3
17 1.150 1.04 close to 1.0 mm² Specialised equipment and connection cables
16 1.291 1.31 between 1.0 and 1.5 mm² Higher-capacity US equipment cables, e.g. 16/3
14 1.628 2.08 close to 2.5 mm² Greater headroom in terms of current-carrying capacity and length, depending on the type
12 2.053 3.31 between 2.5 and 4.0 mm² Higher currents / longer cables, depending on approval

Important: European nominal cross-sections such as 0.75 / 1.0 / 1.5 / 2.5 mm² are standardised sizes. AWG values are often close to these, but do not always correspond exactly.

Converting AWG to mm²: Formula for engineering and data sheets

The conductor diameter of an AWG conductor can be calculated from the AWG number:

d(mm) = 0,127 · 92^((36 − AWG) / 39)

The cross-sectional area is then calculated from the diameter:

A(mm²) = π · (d / 2)²
Example: AWG 18

AWG 18 corresponds to a conductor diameter of approximately 1.024 mm and a cross-sectional area of approximately 0.82 mm².

Example: AWG 16

AWG 16 yields a calculated conductor diameter of approx. 1.291 mm and a cross-sectional area of approx. 1.31 mm².

Practical application for US power cables

For US power cables, AWG is an important indicator of conductor gauge. Typical specifications include, for example, 18/3 or 16/3.

  • 18/3: AWG 18 with 3 wires, commonly found in US appliance leads.
  • 16/3: AWG 16 with 3 conductors, offering greater headroom in terms of length and load.
  • SVT / SJT / SJTW: The cable type and approval are just as important for assessment as AWG.

No blanket current rating: AWG alone cannot be used to determine a safe permissible current for every cable. Connectors, cable type, temperature, certification and application must all be considered together.

Practical considerations for data and patch cables

For network and data cables, AWG often refers to the conductors within the wire pairs. Here, the focus is less on high currents and more on signal quality, attenuation, range and mechanical properties.

  • AWG 26: commonly used in more flexible patch cables.
  • AWG 24 / AWG 23: commonly used in higher-quality or installation-specific data cables.
  • Consider the cable construction: shielding, category, conductor type and length are crucial.

Suitable cables and further MAG guides

When selecting a product, in addition to AWG or mm², the target market, connector type, coupling, rated current, certification, length and operating environment are always important factors.

US power cables

For applications with North American plug systems and typical AWG markings.

View US power cables
Power cables & cross-sections

Guide to selecting 0.75 / 1.0 / 1.5 mm² for power cables.

Cross-section guide
Cable designations

Explanation of markings such as H05VV-F, 3G, 3X, material and construction.

Reading cable designations
Request selection assistance Use the product search

FAQ on AWG and cable cross-sections

What is AWG, explained simply?

AWG is a North American unit of measurement for conductor size. The smaller the AWG number, the thicker the conductor and the larger the cross-section.

What AWG ratings are common for US power cables?

AWG 18 and AWG 16 are common, for example, labelled as 18/3 or 16/3. The correct choice depends on the cable type, certification, length and application.

Is AWG directly comparable to mm²?

For technical guidance, yes. AWG values represent calculated cross-sections, whilst European mm² specifications are often standardised nominal values. Therefore, the conversion provides a very good guide, but is not always an exact 1:1 correspondence.

Can I work out the permissible current directly from the AWG rating?

Not across the board. The permissible current depends not only on the conductor cross-section but also on the cable type, insulation, temperature, installation method, length, connectors, couplings and certification.

Why is AWG also important for data cables?

In data cables, the conductor size influences, amongst other things, attenuation, mechanical robustness and typical installation lengths. Nevertheless, the category, shielding and cable construction must always be taken into account as well.

Note: This information is intended as a technical guide for purchasing, product selection and project planning. The specifications of the specific product, data sheets, standards, approvals and the intended application remain decisive.

Back