AWG Thickness: It Is Not Only About the Wire Gauge

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About AWG Thickness, When choosing an electrically conductive wire, you need to look for many factors. The gauge of the wire is one of them. Picking the correct gauge is essential. For example, some electrical circuits have high amperage ratings, and they need thicker wires to bear the load without getting hot. If you use thin wires in these circuits, it can lead to wire failure. Thus, to avoid all these issues, you need to find a suitable wire.

Table of Contents

What is a Wire Gauge?

The gauge size of the wire or cable defines its thickness. A lower gauge number represents the higher thickness of the wire and vice-versa. The gauge is essential for round and solid lines made from non-ferrous material. It includes only inner copper wire in this cross-sectional area and not the outer jacket.

cable thickness outline icon

Image: cable thickness outline icon

AWG Cable Sizes and Their Unique Properties

The gauge of a wire tells us a lot more than its thickness. With the help of a wire gauge, you can find out the different properties of an individual wire. 

AWG thickness and Diameter:

To calculate the diameter in the AWG system, you need to apply the following formula. The gauge of the wire ranges from low to high numbers, and here smaller numbers represent small diameters while more significant numbers mean larger diameters.

Diameter (AWG)=.005·92((36-AWG)/39) inch

If the gauges are like 00,000,  etc., you can use -1, -2, etc., as it makes sense rather than the “double naught.” Thus, in the AWG wire gauge system, the diameter of the wire doubles for every six gauge decrease. 

On the other hand, the wire’s cross-section area doubles for every three gauge decrease. Mario Rodriguez gave another approximate but more accurate formula for this.

D = .460 * (57/64) (AWG +3) or D = .460 * (0.890625) (AWG +3)

AWG thickness and Metric Wire Gauges

When considering the Metric Gauge System, the wire gauge is ten times its diameter (in mm).

Thus, a 60-gauge metric wire has a diameter of 6mm. It is essential to note that the diameter increases as the wire gauge decreases in the AWG system. However, on the metric scale, it is the reverse. So, metric-sized wires have a diameter in millimeters instead of the metric gauges mostly.

large diameter electrical wires

Image: large diameter electrical wires

Wire Gauge and Load Carrying Capacities

Ampacity refers to the current capacity in amps a wire can carry safely. When calculating a cable’s capacity for maintaining current, you must consider its cross-sectional area. 

Depending on the load requirement, you can choose the correct ampacity wires for your application using the AWG table (below). However, these ratings are only indicative. It would be best to consider the temperature limits of insulation, thermal conductivity, ambient temperature, the thickness of insulation, and air convection.

Wire gauge and resistance:

The wire’s electrical resistance depends on its length and thickness. It means the more the wire’s length, the higher its resistance will be. If two wires are of the same size, the wire with more thickness will have lesser resistance than the thinner wire.

Wire Gauge Maximum Frequency for 100% Skin Depth

When a wire conducts a high-frequency Alternating Current, the current flows along with the outer side of the cable. As a result, its effective resistance increases. The maximum frequency of the wire for 100% skin depth helps you in high-frequency AC engineering. In the below table, you can see the frequency of the wire when the skin depth and the wire radius are equal. This frequency indicates that above these numbers, you must consider the skin effect while calculating the resistance of the wire.

AWG Thickness and breaking force of copper wire:

In the below table, you can see the breaking force of the copper wire. The test results are for nick-free and soft annealed copper wire. The tensile strength of the copper wire used in this testing is 37,000 pounds per sq. inch.

AWG Wire gauge chart
AWG Wire gauge chart
AWG Wire gauge chart

Image: AWG Wire gauge chart

Typical Applications of Standard Wire Gauges

The different gauges of wire give it other electrical properties. Thus, you can use each wire for a unique application only. For light-duty electrical work, you have to choose higher gauges, and on the contrary, heavy-duty jobs need lower gauge wires. You can calculate the gauge of wire with the help of a wire gauge calculator.

These are some of the applications of the wire with their AWG sizes:

  • 18-gauge wire: You can use it for low voltage lighting and cords
  • 14-gauge wire: suitable for residential wirings like light fixtures, household outlets, and devices.
  • 12-gauge wire: ideal for residential wiring in small appliances or small AC units
  • 10-gauge wire: with this gauge, you can use wires in larger household devices like heaters,  clothes dryers, or window AC units.
  • 8-Gauge wire: suitable for electric ranges, ovens, and split and window AC units.
  • 6-gauge wire: ideal for kitchen cooktops and other heavy electric ranges
  • 4-Gauge wire: best for large furnaces and giant factory heaters.


To ensure that an electrical system runs properly, you must pick the correct wire. However, selecting a suitable wire for a particular application can be challenging. Our experts have rich experience in handling wires and cables, and our experts have the right skills and knowledge to help you pick the correct cables and cables for your needs. You can contact us for further information and help. We can also give you a quote for your requirements.