Any new electrical wiring work must be done carefully, whether in the home or workplace. Suppose you are not familiar with electrical gauges and amp ratings. This article will ease you into the learning process.
Soon you’ll be checking your electrician’s work like a pro. Keep reading to find all the tips to ensure the safest and best 2 through 20 gauge wire & amp rating.
Summary
The best way to find the gauge wire amp rating is by using the AWG wire size chart below. From it, you’ll discover the following.
- The amp rating for 2 gauge wire is 90 amps at 167°F ambient temperature using copper.
Table of Contents
THHN wire size chart
You no longer need calculators, resources, or tables scattered around the internet. Here is the THHN wire size chart you need. You’ll easily see the values and load the different options can handle, including ambient temperatures. Fining out ampacities is no longer hard for your power cable!
| Copper | Copper | Copper | Aluminum | Aluminum | |
| Wire Gauge Size | 90°C (194°F) THWN-2, THHN, XHHW-2, USE-2 | 75°C (167°F) THW, THWN, SE, USE, XHHW | 60°C (140°F) NM-B, UF-B | 90°C (194°F) XHHW-2, THHN, THWN-2 | 75°C (167°F) THW, THWN, SE, USE, XHHW |
| 14 | 25 | 20 | 15 | — | — |
| 12 | 30 | 25 | 20 | 25 | 20 |
| 10 | 40 | 35 | 30 | 35 | 30 |
| 8 | 55 | 50 | 40 | 45 | 40 |
| 6 | 75 | 65 | 55 | 55 | 50 |
| 4 | 95 | 85 | 70 | 75 | 65 |
| 3 | 115 | 100 | 85 | 85 | 75 |
| 2 | 130 | 115 | 95 | 100 | 90 |
| 1 | 145 | 130 | — | 115 | 100 |
| 1/0 | 170 | 150 | — | 135 | 120 |
| 2/0 | 195 | 175 | — | 150 | 135 |
| 3/0 | 225 | 200 | — | 175 | 155 |
| 4/0 | 260 | 230 | — | 205 | 180 |
| 250 | 290 | 255 | — | 230 | 205 |
| 300 | 320 | 285 | — | 260 | 230 |
| 350 | 350 | 310 | — | 280 | 250 |
| 500 | 430 | 380 | — | 350 | 310 |
| 600 | 475 | 420 | — | 385 | 340 |
| 750 | 535 | 475 | — | 435 | 385 |
| 1000 | 615 | 545 | — | 500 | 445 |
What is a gauge, and what are its types?
The gauge of a wire refers to its diameter and hence its current carrying capacity.
Different parts of the world use different standards for measurement. Here are the most popular types:
- IEC 60228: This is the standard set by the International Electrotechnical Commission on international conductors of cables. It is the wire-size measurement standard used in most parts of the world.
- AWG: American Wire Gauge is another standardization system in use since 1857 in North America. Today, this system is widely adopted in the United States and Canada. Like many other non-metric systems, the increasing number of AWG automatically denotes a decreasing diameter. This is similar to the British Standard Wire Gauge system. Apart from electrical wires, it is also used to denote the sizes of body piercing jewelry.
- SWG: Standard Wire Gauge refers to the unit used to measure the thickness given by British Standards in 1964. Although originally widely adopted, it is in use in very small areas now. Today, it is only known to be used to measure guitar strings and some cables.
