AWG – American Wire Gauge: Everything About Wire Diameter, Resistance, and Current Rating

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American Wire Gauge (AWG), also known as Brown & Sharpe Wire Gauge, is a standardized system for determining the wire gauge of electrical conductors. This measurement system is primarily used in North America but has gained worldwide acceptance due to globalization.

The AWG system specifies wire diameter, electrical resistance, current capacity, and the appropriate cable cross-section for specific applications. It is used for both solid copper wires and stranded metal conductors.

The term gauge refers to the thickness of a wire. The following applies in the AWG system:

The lower the AWG number, the larger the wire diameter.

The higher the AWG number, the smaller the wire diameter.

A 0000 AWG (4/0 AWG) wire, for example, has a diameter of 11.68 mm, while a 36 AWG wire measures only 0.127 mm.

Choosing the right wire gauge has a decisive influence on electrical conductivity, resistance, and cable insulation. A thicker copper wire has lower resistance and can therefore transmit more current, while thinner wires tend to have higher losses.

1. Electrical Resistance

The thinner the wire, the higher the electrical resistance. This can lead to a voltage drop, especially with longer cables.

2. Current and Temperature Increase

A thicker metal conductor can carry a higher current without overheating. An insufficient wire gauge can lead to overheating and increase fire risks.

3. Insulation and Protection

The insulation of a cable determines the maximum voltage that a conductor can safely carry. In cable assembly, AWG values are therefore combined with the appropriate insulation.

The German translation of AWG is 'Amerikanische Drahtlehre' (American Wire Gauge), but it can also refer to 'American Cable Gauge'.

As the cable cross-section is usually specified in square millimeters (mm²) in Europe, converting AWG to mm² is often necessary. You can easily use our free AWG converter for this purpose.

Diameter Calculation

The diameter calculation is based on a logarithmic formula that defines the ratio of successive AWG sizes:

Similarly, the AWG number can be calculated from the diameter:

The formula for cross-section calculation is as follows:

or

Wires with a stranded or fine-stranded structure have an overall diameter about 13-14% larger due to the gaps between individual strands. This is particularly important in cable assembly and system technology, as the correct diameter is crucial for electrical conductivity and mechanical stability.