How Many Amps Can 8 Gauge Wire Handle ( Ampacity Charts)

The 8 gauge cables mostly provide current to different appliances connected at homes. But these wires come with different amp ratings based on some parameters. For finding the value of the home many amps 8 gauge wire can handle wire material and the highest operating temperature is important. At 90 degrees, 8 gauge copper wire can handle 55 amps, and aluminum material can handle 45 amps. So let’s get started with How Many Amps Can 8 Gauge Wire Handle ( Ampacity Charts)

 8 Gauge Wire Material

The commonly used materials to make 8 gauge wire are copper and aluminum. Copper wire comes with larger current-carrying features than aluminum, so 8 AWG copper wire can carry more current than 8 AWG aluminum wire

 8 Gauge Operating Temperature

Electrical wires can have different materials as insulation. These materials can handle the heat produced by current passing in wires and are rated to the highest temperatures. Normally insulation comes with a rating of 60. 75 and 90 degrees in NEC.

How Many Amps Can 8 Gauge Wire Handle

Number of Wires

The 8 gauge cables normally are in 8/2, 8/3, and 8/4 types which means that number of 8 gauge wires in cables. Normally they have one ground wire. For example, 8/2 cable has 2 wires of eight gauge, 8/3 has 3 wires of 8 gauge and 8/4 has 4, 8 gauge wires.

Conductor count Correction for the current rating
4 – 6 80%
7 – 9 70%
10 – 20 50%
21 – 30 45%
31 – 40 40%
41 and above 35%


The accepted ampacity of 8 AWG is based on the conductor used, the thickness of the conductor, and the temperature. According to NEC the 8 AWG amp rating of copper THHN/THWn 2 for ninety degrees is 55 amps. The similar for copper made XHHW/XHHW-2, RHH/RHW-2, and USE-2. The 8 AWG copper cable is the best to use for cable for medium-load applications.

Copper cables rated for temperatures about seventy centigrade, like RHW, XHHW, THHW AWG 8 wire rating is 50 amps. TW/UF copper cables can handle 40 amps for 60 centigrades. Since TW and UF insulation are rated for lower temperatures.

Ampacity ratings are correct for wires used in free air since air dissipates easily in air, and there is no insulation effect from the environment and handle from neighboring cables. For copper cables in conduit amp rating for 8 AWG wire THHN/THWN-2 is about 40 Amps, and the ampacity of TW/UF is near 35 Amps.

Applicable wire material for 8 gauge wire amps 120v

Current (amps) 25 feet 50 feet 100 feet 150 feet
15 Copper or Aluminum Copper or Aluminum Copper or Aluminum Copper only
20 Copper or Aluminum Copper or Aluminum Copper used Larger size wire need
30 Copper or Aluminum Copper or Aluminum Larger wire needed larger wire needed
40 Copper only Copper only Larger wire needed larger size needed

8 Gauge Marine/Automotive Wire

Marine/automotive 8 gauge wires are normally stranded 8 gauge copper wire with high resistance to mechanical wear, low and high temperature, and acidic and alkaline conditions. For increasing durability, some manufacturers provide stranded copper wires with tinned copper strands to increase resistance to oxidation and chemical reactions.

8 Gauge Wire Cables: 8/2 Wire, 8/3 Wire, and 8/4 Wire

The electric cable comes with different wires combined with each other. The real number of wires changes based on cable use. So cables created with the use of 8 gauge wires are denoted with 8/2 wire, 8/3 Wire, and 8/4 Wire. When the cable is denoted as like 8/3 Wire it means that cable has 3  eight gauge wires conductors and one ground wire so

Wire Type Number of Conductors Gauge
8/2 Wire (8 2 Wire) 2 8 gauge
8/3 Wire (8 3 Wire) 3 8 gauge
8/4 Wire (8 4 Wire) 4 8 gauge

How Many Amps Can 8 AWG Aluminum Wire Handle?

For aluminum cables, the ampacity of 8 AWG is less since lower copper conduction.  It is 45 amps for  THHN/THWN-2, RHH, XHHW-2,  and USE-2; 40 Amps for THHW, RHW,  and XHHW, and 30 Amps for TW/UF. In conduit, it will be 30 to 35 Amps for THHN or XHHW and 25 to 30 amps for UF insulation.

 8 Gauge Wire amps

8 AWG THHN/THWN-2 Specifications

Size: 8 AWG
Number of Strands: 19
PVC Insulation Thickness (Conductor): 0.760 mm
Nylon Jacket Thickness: 0.130 mm
Outside Diameter: 5.39 mm
Weight: 0.069 lbs per ft

 Applications of 8 AWG Cables

The 8 AWG is a commonly used wire size for medium loads in residential, commercial, and industries. Some common uses are

  1. It is used for larger branch circuits used for certain needed devices
  2. It is used to provide power to subpanels, especially when distance is not high and demand is not high
  3. Due to high current uses many central AC units or heat pumps use 8 AWG wire for circuits.
  4. Larger water heaters especially tankless use eight WG wires.
  5. Larger motor-like pumps can use 8AWG wire based on motor current uses and starting ampere.
  6. Different household ovens and ranges needed larger cables about 6 AWG or larger some small units or models used for apartments use 8 AWG wires.
  7. Some hot tubes with multiple heaters or pumps can need 8AWG wire for circuits

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