Understanding and correctly applying the AWG table

In industrial electrical engineering and cable assembly, the precise selection of conductor cross-sections plays a central role in functional safety and operational reliability. The American Wire Gauge system (AWG) has become established internationally as the standard designation for wire sizes, especially for imported components, international projects and automation technology. Anyone who interprets AWG numbers correctly and uses the corresponding table confidently avoids sizing errors, optimises electrical cables and ensures standard-compliant wiring. This article explains the logic behind the AWG system, shows how to work with conversion tables in practice and provides guidance for typical applications in industry and mechanical engineering.

Table of contents

1. Key points at a glance
2. What does AWG mean and why is it important?
3. How do you read an AWG table correctly?
4. Which AWG size for which application?
5. Avoiding common mistakes when choosing AWG
6. Conclusion

Key points at a glance

• AWG is an American standard for coding wire diameters. A higher AWG number indicates a thinner wire.
• Conversion tables link AWG numbers to metric values such as cross-section in mm² and diameter in mm.
• The right AWG size depends on current-carrying capacity, voltage drop and mechanical stress.
• Mistakes in cable selection lead to overheating and increased conductor resistance and can endanger systems.

What does AWG mean and why is it important?

The American Wire Gauge system originated in the USA as a standardised method for designating wire and cable cross-sections. The coding is based on a historical drawing process: the more often a wire was drawn through a drawing die, the thinner it became and the higher its AWG number. This inverse logic still shapes the system today: AWG 10 describes a thicker conductor than AWG 24, even though the number is lower. This peculiarity often confuses development engineers and buyers who work primarily with metric units.

So why is AWG still so relevant? In globalised supply chains and with assembled cables from international production, technical data is often given in American notation. Control cables, flexible cables for drive technology or highly flexible strands in automation are frequently specified with AWG values. Anyone who reliably converts this designation into metric data avoids misunderstandings in procurement, design and technical documentation.

How do you read an AWG table correctly?

An AWG conversion table links the American wire size to the metric units commonly used in Europe. The most important information in such a table includes the AWG number, the diameter in millimetres and the cross-section in square millimetres. It often also lists conductor resistance in ohms per kilometre or metre, maximum current-carrying capacity and the strand structure for flexible versions.

AWG	Cross-section (mm²)	Conductor resistance (ohm/km)
10	5.26	approx. 3.3
14	2.08	approx. 8.5
18	0.82	approx. 21.6
22	0.33	approx. 54.6
24	0.20	approx. 86.9
28	0.08	approx. 219.8

The conversion is based on a geometric formula: the AWG system follows a logarithmic progression in which the cross-section roughly doubles every 3 AWG steps and the diameter every 6 AWG steps (smaller AWG number), or halves (larger AWG number). The cross-section can be calculated from the diameter using the circle formula. The system has no intermediate values between the standard AWG numbers; discrete steps are defined. In practice, you work exclusively with the standardised AWG numbers listed in tables. For assembled products and technical data sheets, a precise overview is essential to evaluate electrical properties and ensure standard-compliant designs.

Which AWG size for which application?

Choosing the right cable cross-section is based on two key criteria: current-carrying capacity and the tolerable voltage drop over the cable length. A conductor that is too thin overheats at high currents, while excessive conductor resistance increases the voltage drop and can impair the function of sensitive electronics. In industry, different AWG sizes are used depending on the purpose:

• AWG 10 to AWG 14: supply cables for machines, drives and load circuits with higher currents, typical in control cabinets and power distribution
• AWG 16 to AWG 20: control cables, signal cables and connections in automation technology, where moderate currents and good flexibility are required
• AWG 22 to AWG 28: data cables, USB cables, sensor wiring and fine connection technology, where small cross-sections and high flexibility come first

Besides the electrical design, mechanical strength plays an important role. Highly flexible strands with a fine strand structure are suitable for moving applications such as drag chains or robotics, while solid wires are standard in fixed installations. Insulation materials, from PVC and silicone to FEP, also influence operating temperature, chemical resistance and fire behaviour. In cable assembly, we take these parameters into account to deliver precisely fitting solutions for every application.

Avoiding common mistakes when choosing AWG

A classic mistake in practice is choosing cables that are too thin for reasons of space or cost, without considering the actual current load. The result is increased resistive losses, heating of the cable and, in extreme cases, damage to the insulation or even a fire hazard. With longer cables in particular, the voltage drop adds up and impairs the function of sensors, actuators or control components. Careful calculation based on the maximum current consumption and cable length is therefore essential.

Another aspect is often underestimated: mechanical flexibility. Solid wires with few strands break under repeated movement, while cables that are too stiff are damaged in tight bending radii. Dynamic applications require highly flexible versions with a suitable strand structure. The AWG number alone says nothing about this. Confusing AWG with other codings such as MCM (thousand circular mils) or MIL specifications can also lead to incorrect orders. Anyone who checks technical data carefully and draws on cable assembly expertise when in doubt minimises risks and secures project quality.

Conclusion

The AWG table is an indispensable tool for the safe and standard-compliant design of electrical cables in industry and mechanical engineering. Understanding the inverse logic (a higher AWG number means a thinner wire) and converting correctly to metric values form the basis for reliable cable selection. Current-carrying capacity, voltage drop and mechanical requirements determine which AWG size is suitable for each application. Common mistakes such as undersizing or a lack of flexibility can be avoided through precise planning and the use of verified conversion tables.

At SICATRON, we support you from technical advice and the selection of suitable cable cross-sections to the finished assembly, always with an eye on quality, safety and your specific project requirements. Use our experience in electrical engineering to design your wiring optimally and implement reliable solutions for the long term.