How Many Amps Can a 16 Gauge Wire Handle? (120 Volts, 12 Volts)

How Many Amps Can a 16 Gauge Wire Handle

For general purposes, 16 gauge wire is found in extension cords and used in all the ways extension cords are normally used, such as leaf blowers, hedge trimmers, or connecting appliances across the house. It’s also found in vehicles, sometimes in large quantities.

So, how many amps can a 16 gauge wire handle? Sixteen gauge wire can handle 13 Amps. Unlike most residential wiring, in the 12 to 14 gauge range, there’s not much that 16 gauge wire is used for, except for automobiles. 

Sixteen gauge, copper wiring isn’t even listed in the NEC code, articles 310 to 316 with a lone exception. Under the temperature rating of 90ºC, 16 gauge wire is rated as capable of conducting 18 Amps. 

For vehicles, however, the relative obscurity of 16 gauge wiring is irrelevant, as it’s used quite a bit. So 16 gauge isn’t useless to be sure, it’s just not found much in the way of residential applications and commercial construction.

Uses For Sixteen Gauge, Copper Wire

As stated before, 16 gauge wire is commonly found in extension cords but it also has a lot of uses in automobiles.

You’ll find 16 gauge in the headlights, parking lights, turn signals, ignition coil, starter, interior lights, and alternator. 

It’s not always used in those particular devices, but you will typically find it there in most makes and models.

Electrical wiring in vehicles often seems to be a forgotten art, relegated to the back pages of some ambiguous blueprints. 

No one notices much about electrical wiring in vehicles until something goes wrong. 

Read also: How Many Amps Can a 12 Gauge Wire Handle (220 Volts)

Is Aluminum Used In Sixteen Gauge Wire?

Because of its inherent resistance to current—Aluminum builds up a layer of oxide on its surface as electricity passes through it, serving as an effective resistor—you won’t find 16 gauge wires made of aluminum. Of course, there may be an exception or two out there.

To effectively match 16 gauge, copper wiring, at a temperature rating of 90ºC, that’s pulling 18 Amps, you would need 12 gauge aluminum wiring, which is rated at 20 Amps across ⅔ of the temperature ratings. It increases to 25 Amps at 90ºC.

Twelve gauge wire is noticeably thicker than 16 gauge. Aluminum requires a higher gauge to channel the same level of current that copper does because of its resistance factors. 

Think of it as a much wider tunnel, going from a two-lane highway to a four-lane highway. However, the four-lane highway tunnel is restricted by a sudden, 45º turn just before the entrance, along with a narrow three lanes within the tunnel itself. 

While being a thicker gauge than copper wire, aluminum is restrictive to the point of negating the benefits of a lower gauge conductor.

Read also: How Many Amps Can a 14 Gauge Wire Handle (Best Tips)

Is Sixteen Gauge, Copper Wire Restricted To Just 13 Amps In All Applications?

According to the NEC Code of allowed ampacities, the 16 gauge wire handles 18 amps at a 90ºC temperature rating. However, it is commonly used in extension cords at a lowered ampacity.

Automobile applications are entirely different. There are a lot of applications for the 16 gauge wire and they carry for more amperage than is typical or what is stated in the NEC. 

  • 3 feet is typically 50 Amps
  • 30 Amps at 5 feet
  • Between 18 and 30 Amps for 10 feet
  • 8 to 12 Amps at 20 feet
  • 8 to 10 Amps at 25 feet

These wires are not used for constant operation at that range but mostly as start-up amperage.

They’re also insulated with premium materials that can withstand the heat generated from channeling well above 18 Amps, even if it isn’t for extended periods. 

As discussed above, there is far more utilization for 16 gauge wire in a vehicle system rather than for residential and commercial use. 

Read also: How Many Amps Can a 10 Gauge Wire Handle (Best Tips)

What Else Can Sixteen Gauge Wire Handle?

Sixteen gauge wires are often used in home theater systems and car audio components. Surround sound home audio systems, in cases where the surrounding speakers don’t have to be separated too much, 16 gauge wire is ideal.

They don’t work as well when they are extended too far, such as several yards or connecting an amplifier to a speaker that is in another room. 

Eight and sixteen-ohm speakers are perfect for 14 and 16 gauge wiring. Anything larger can cause audio distortion, capacitance problems, and garbage signal quality. 

If you’re gauging (pun absolutely intended) the price on any particular system, going with a system that functions well with 14 and 16 gauge wiring will save a lot of money. 

Copper doesn’t carry the same value like gold and silver, but that doesn’t mean it lacks any value. The thicker the gauge—lower the number—the more expensive it gets. This is especially true if you plan on running a lot of it. 

The same applies to car stereo systems, with 8 and 16-ohm speakers requiring 16 gauge wiring, so long as its length isn’t so far as to make it inefficient.

How Long Will Sixteen Gauge Wire Run Before A Voltage Drop?

The voltage drop for a 10 Amp load across 100’ of 16 gauge wire, is 8V. At ten feet, it’s .08V.

The standard maximum length for running a 16 gauge speaker wire is 48 feet before the resulting voltage drop begins to affect the system.

If we know that .08V is the amount of voltage drop per ten feet then you can calculate the drop at 300’. 300/100 x 8 = 24V. 

As you can see, 16 gauge wire isn’t at its best when stretched over long distances and it can only conduct so many Amps, to begin with. 

Can You Tie Sixteen Gauge Wire Into Eighteen or Fourteen?

Legally, the minimum wire size for use with AC (alternating current) is 14AWG or gauge. So connecting a 16 gauge wire to a 14 gauge wire that’s running from a circuit breaker is hazardous at best. 

However, in audio applications—or inside a vehicle—intermixing 14, 16, and 18 gauge wires is acceptable, so long as they are properly insulated.

You also have to beware of how much current, normally meant for 14 gauge, is running through 16 gauge and for how long.

Eighteen gauge, like 16 is used most often in automobile and stereo applications, always off of DC (direct current) battery power. It can be intermixed with 16 gauge wire where its practical and efficient to do so. 

Sixteen and eighteen gauge wires aren’t listed in the NEC articles, 310 to 316 because they are rarely if ever applied to AC voltage.

The 16 gauge only applies when it is temperature rated at 90ºC and can pull 18 Amps.

Last But Not Least

Sixteen gauge wire is literally last and least on the NEC codes for ampacity. While it can still carry a reasonable amount of Amps, its generally only used efficiently under battery power such as from vehicles, boats, and even RVs to an extent.

Sixteen gauge is also popular in stereo systems and while home theater systems plug into an outlet and draw AC, the 16 gauge wire itself is used minimally as a connection between speakers. 

That connection is usually from the amplifier, into and out of bass speakers, and the in/out of tweeters and smaller, background speakers.

Regardless of how it’s used, there are plenty of applications for 16 gauge wires, even if it’s not one of the most recognized wire sizes. 

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Jeff is an automotive technician, technical writer, and Managing Editor. He has held a lifelong passion for cars, with a particular interest in cars like the Buick Reatta. Jeff has been creating written and video content about transportation, automotive, electric cars, future vehicles as well as new, used for more than 18 years. Jeff is based in Boulder, Colorado.

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