10 Gauge Wire: How Many Amps Can 10 Gauge Wire Handle?
10 gauge wire is a very popular wire thickness, very often used for speakers, extension cords, home wiring, and other electric systems where wires able to handle 20-30 Amps are required.
However, actual current carrying ability (Ampacity) also depends on the wire length, maximum wire surface temperature, and similar.
Published: May 2, 2022.
How Thick is 10 Gauge Wire?
10 gauge wire or AWG 10 wire features physical dimensions of:
- diameter: 0.1019 inches (2.5882 mm, 10.4 kcmil),
- area: 0.0082 inches2 (5.2612 mm2),
- Ampacity (default): 30 Amps @60°C/140°F, 35 Amps @75°C/167°F, 40 Amps @90°C/194°F.
So AWG 10 wire (10 gauge wire) is ~0.1 inch (~2.6 mm) thick without insulation.
10 Gauge Wire Amps
Default 10 gauge wire Ampacity (the wire's ability to carry current) is 30 Amps @60°C/140°F, 35 Amps @75°C/167°F, or 40 Amps @90°C/194°F.
In most situations, one uses Ampacity provided for 75°C/167°F temperature, but there are few rules that have to be applied before finding the actual current that AWG 10 wire can handle.
80% rule means that the actual Ampacity is 80% less than the default Ampacity for any given temperature, for example:
Ampacity @60°C/140°F = 30 Amps * 0.8 = 24 Amps
Ampacity @75°C/167°F = 35 Amps * 0.8 = 28 Amps
Ampacity @90°C/194°F = 40 Amps * 0.8 = 32 Amps
So, for safety reasons the Ampacity of 10 gauge wire @75°C/167°F is not 35 Amps but 28 Amps - for shorter wires.
As the wire length is increased, energy losses are increased. Thus, in order to keep the losses to an acceptable level, one has to take into account the wire length - for every 50 feet, 10% smaller Ampacity.
For example, the actual Ampacity for a 100 feet long 10 gauge wire with the maximum allowed surface temperature would be:
Ampacity = 35 * 0.8 / 1.2 = 23.33 Amps
The following chart lists the Ampacity of 10 gauge wire at certain temperatures for the wires of 50, 100, 150, and 200 feet.
|Wire Length / Temperature||@60°C/140°F||@75°C/167°F||@90°C/194°F|
So, if You wonder how many Amps will 10 gauge wire carry, check the chart - in most situations 75°C/167°F temperature is good to go - and read the values:
- for shorter wires, 10 gauge wire can handle ~28 Amps,
- ~50 feet (~15.25 m) 10 gauge wire can handle ~25.4 Amps,
- ~100 feet (~30.5 m) 10 gauge wire can handle ~23.3 Amps,
- ~150 feet (~45.75 m) 10 gauge wire can handle ~21.5 Amps,
- ~200 feet (~61 m) 10 gauge wire can handle ~20 Amps.
Note: the actual surface temperature due to the current flowing through the wires will be lower, but to keep calculations simpler, maximum allowed currents are calculated using these formulas - the actual goal is to keep energy losses low in longer cables.
Long Story Short: never use thinner wires than required - energy losses will increase, wire temperatures will increase, the danger of fire or some other accident will increase, etc.
Personally, when checking the tables and charts and when doing calculations, go for 60°C/140°F values - it is always better to have some safety margin even if that means having cables and wires slightly over-dimensioned - safety first ...
Whatever You do - it is your own responsibility. And of course, stay safe.