Wire Gauge

A Guide to Wire Gauge Sizes

Wires come in different thicknesses—i.e., gauges—each of which is suited to different purposes. For example, craft wire is thin to support bending, forming, and twisting into jewelry and other craftwork. In the following guide, we provide an overview of what wire gauges are, why they’re important, key considerations, and standard sizes available to help industry professionals select the right wire gauge for their application.

What Are Wire Gauges?

The gauge of a wire refers to its thickness. Each gauge is represented by a number, with smaller numbers representing thicker wire gauges and higher numbers signifying thinner wires.
American Wire Gauge (AWG) is a standard method of measuring and identifying cable thickness developed in the United States for electrically conductive wire. It is suitable for specifying gauges for round and solid conductive wires made from non-ferrous material. As a wire’s thickness affects its electrical properties (e.g., resistance and load-carrying capacity), knowing the gauge of a wire allows industry professionals to quickly and easily determine whether it is appropriate for a specific application. This knowledge can also be communicated between different parties, such as from the manufacturer to the consumer.

Considerations for Wire Gauges

When selecting an electrically conductive wire for an application, gauge is an important design consideration. However, the right gauge depends on a variety of factors. For example, electrical circuits with higher amperage ratings require thicker wires to accommodate the load without experiencing excessive heat buildup. Using wires that are too thin for the specified circuit amperage can result in wire failure or ignition. Avoiding these issues necessitates identifying the total amperage of a system—by calculating the effects of the planned load, the connected load, and the circuit length—and choosing a wire that is appropriate for it.

Relationships Between Wire Gauge and Other Technical Specs

The gauge of a wire imparts more than information about its thickness. Given its gauge, industry professionals can determine the following about a particular wire:

  • Diameter. Wire gauges range from low numbers to high numbers, with smaller numbers referring to smaller diameters and larger numbers representing larger diameters. For example, AWG 4 is 0.2043 inches in diameter, and AWG 40 is .0031 inches in diameter. The diameter doubles every time the gauge decreases by six levels (e.g., a three-gauge wire has double the diameter of a nine-gauge wire).
  • Area. The cross-sectional area of round wires can be calculated using the formula A= πr2, with r representing half of the diameter. The wire’s cross-sectional area doubles every time it descends three levels (e.g., a six-gauge wire has double the cross-sectional surface area of a nine-gauge wire).
  • Feet per pound. Feet per pound refers to the number of feet of wire needed to reach one pound in weight. (e.g., AWG 4 wire requires 7.918 feet, while AWG 40 requires 34.364 feet.)
  • Resistance (ohms per 1000 feet). A wire’s electrical resistance depends on its length and thickness. Longer wires provide greater resistance than shorter wires. Given two wires of the same length, the thicker wire would have smaller resistance than the thinner wire. (e.g., At 25° C, AWG 4 wire has a resistance of .2485Ω for 1000 feet, while AWG 40 wire has a resistance of 1079Ω for 1000 feet.)
  • Current capacity (amps). Current capacity is a measure of the amount of current a wire can carry safely. As lower gauge wires (such as AWG 4) are thicker, they can accommodate more electrons than higher gauge wires (such as AWG 40).

Applications for Different Wire Gauges

As each wire gauge carries different physical and electrical properties, they are generally suitable for different purposes. Thinner gauges usually find application in more lightweight applications, while thicker gauges are employed for heavy-duty applications.
Some common use cases for different wire gauges are outlined below:
Gauge 4…………………………………………………………………. furnaces and large heaters
Gauge 6……………………………………………………………….. kitchen cooktops and ranges
Gauge 10………………………………………… clothes dryers, large AC units, and water heaters
Gauge 12……………………………………………………. residential outlets and small AC units
Gauge 14…………………………………………………… lighting fixtures, devices, and circuits
Gauge 16……………………………………………………………….. light-duty extension cords
Gauge 18…………………………………………………………… low-voltage lighting and cords

Wire Gauge Size Chart

American Wire Gauge standards range from 0000 (which can handle up to 302 amps) to 40 (which can handle up to 0.0137 amps). Most household and commercial wiring demands range from 2 (95 amp maximum) or 3 (85 amp maximum) to 14 (15 amp maximum). In the table below, we outline all of the AWG cable sizes and their unique properties.

wire gauge sizes table

Partner With Precision Manufacturing Company for High-Quality Wire

Choosing the right wire, including in regard to gauge, is important to ensuring an electrical or electronic system runs as intended. However, determining which one is right for a specific application can be challenging. For these situations, Precision Manufacturing Company is here to help. Equipped with over five decades of experience handling wires and cables, we have the skills and knowledge to help with any wire or cable need.

For additional information about our capabilities or assistance choosing a wire for your application, contact us or request a quote today.