Difference Between a 10 and 12 Gauge Extension Cord

Shopping for the best extension cord can be a painstaking process, especially for novice shoppers. But it's a process that demands utmost diligence.

The right extension cable can prolong the durability of electrical appliances it's used with. On the other hand, an improper cord can cause electric malfunctions. These faults threaten the performance of your electrical equipment and could also put you and your other household members at risk of electrocution.

Thickness (also known as gauge) is one of the core aspects to consider when shopping for extension cords. These wires come in varying gauges, and it's essential to choose a cable with a thickness that matches its current handling capacity.

10 and 12 are among the most common extension wire gauges. But what's the difference between these two thickness ratings? That question shall form the basis of this article.

What Is An Extension Cord?

We should probably back up and define these electrical accessories before we explore the differences between a 10 gauge and a 12 gauge extension cord.

An extension cord is variously known as an extension cable, extension lead, power cable, power extender, and drop cord. It refers to a length of flexible electrical power cable length designed with a plug on one end and an outlet on the other. The outlet can constitute one or more sockets.

Extension cords are used primarily to bridge the gap between the electrical outlet and electrical appliances. These cables allow you to utilize the equipment beyond its standard power cord length.

Based on the core function of power extenders, it's understandable why length is usually the primary consideration when choosing these cables. However, the length of a power cord will only allow it to shorten the distance between the main electricity supply and the equipment you wish to power. It won't always directly affect the wire's current handling capacity.

To select the best extension cord for your home or office appliances, you need to consider length and thickness. And that's where a 12 versus 10 gauge extension cord comparison comes in.

Difference Between a 10-Gauge and 12-Gauge Electrical Cord

The primary difference between a 10-gauge and a 12-gauge electrical cord lies in their thickness.

10-gauge wires are thicker in diameter than 12-gauge wires. It sounds ironic, considering that the number 10 comes before 12.

Interestingly, the gauge ratings of electrical wires are inversely proportional to the actual diameters of such wires. The higher the gauge number assigned to an extension cord, the smaller its diameter. That explains why a 12-gauge cable has a smaller diameter than a 10-gauge cable.

How Big Is A 10-Gauge and 12-Gauge Wire?

When determining the actual thickness of electrical wires, we use the American Wire Gauge (AWG) or the Standard Wire Gauge (SWG) systems.

The American Wire Gauze system, also known as the Brown & Sharpe Wire Gauze, is the standard way of denoting wire thicknesses in North America. This system has been in use since 1857. According to the AWG, the largest standard wire size is 0000 AWG, while the smallest standard wire size is 40 AWG.

The Standard Wire Gauge, also known as the British Standard Gauge or the Imperial Wire Gauge, is a standard for measuring the thickness of wires outside America. This system was established mainly for gauging the thickness of guitar strings. However, it later became popular in other fields, such as the electrical and construction industries. The Standard Wire Gauge has values ranging from 16 mm to 0.02 mm, or 0.5 inches to 0.001 inches.

To work out the thickness of a 12-gauge and 10-gauge extension cable, we'll also need to determine whether the wire is solid or stranded.

Solid extension cables consist of a single solid metal core, while stranded cords have multiple strands of wires carefully wrapped around each other. Stranded wires tend to be thicker than their solid counterparts. That's due to the multiple strands bundled up together. However, solid wires are the standard type. This is why most gauge ratings are based on solid instead of stranded wires.

A solid 12-gauge extension cord has an AWG thickness of 2.053 millimeters. That equates to 0.0808 inches. Since the actual thickness of 12-gauge power cords is closer to two millimeters, these cables are commonly referred to as '2-mm wires.'

A solid 10-gauge wire has an AWG thickness of 2.588 millimeters or 0.1019 inches. That makes 10-gauge cables 26% larger than 12-gauge cables.

10-gauge extension cables are larger than 12-gauge cords if you compare their cross-section area. The cross-section area of 12-gauge cables is 3.31 square millimeters (mm²), while that of 10-gauge wires is 5.26 square millimeters (mm²). In percentages, 10-gauge wires are 59% larger than 12-gauge wires in terms of cross-section area.

Also, as you might have already gathered by now, the difference in diameters of 10-gauge and 12-gauge extension cables only applies to copper wires. It doesn't take into consideration the insulation thickness.

Final Word

10-gauge and 12-gauge extension cords differ fundamentally in their thickness. Remember that thickness determines a wire's current handling capacity.

Therefore, it's clear that 10-gauge cables are better suited for higher-voltage equipment than 12-gauge cords. These include solar panels, inverters, automotive, DC circuits, etc.

On the other hand, 12-gauge cables would be ideal for kitchen and bathroom receptacles and clothe dryers, air conditioners, and water heaters.