AWG wire gauge size chart
AWG is the American Wire Gauge. Diameters are for solid bare copper and follow the AWG formula: each step down the scale multiplies the diameter by 1.1229. The ampacity column is the NEC Table 310.16 value for copper at 75°C, the column most circuit breakers and panels use.
| AWG | Diameter (in) | Diameter (mm) | Area (mm²) | Circular mils | Copper amps (75°C) |
|---|---|---|---|---|---|
| 4/0 | 0.4600 | 11.684 | 107.22 | 211,600 | 230 A |
| 3/0 | 0.4096 | 10.405 | 85.03 | 167,800 | 200 A |
| 2/0 | 0.3648 | 9.266 | 67.43 | 133,100 | 175 A |
| 1/0 | 0.3249 | 8.251 | 53.48 | 105,600 | 150 A |
| 1 | 0.2893 | 7.348 | 42.41 | 83,690 | 130 A |
| 2 | 0.2576 | 6.544 | 33.63 | 66,360 | 115 A |
| 3 | 0.2294 | 5.827 | 26.67 | 52,620 | 100 A |
| 4 | 0.2043 | 5.189 | 21.15 | 41,740 | 85 A |
| 6 | 0.1620 | 4.115 | 13.30 | 26,240 | 65 A |
| 8 | 0.1285 | 3.264 | 8.37 | 16,510 | 50 A |
| 10 | 0.1019 | 2.588 | 5.26 | 10,380 | 35 A |
| 12 | 0.0808 | 2.053 | 3.31 | 6,530 | 25 A |
| 14 | 0.0641 | 1.628 | 2.08 | 4,110 | 20 A |
| 16 | 0.0508 | 1.291 | 1.31 | 2,580 | n/a |
| 18 | 0.0403 | 1.024 | 0.82 | 1,620 | n/a |
| 20 | 0.0320 | 0.812 | 0.52 | 1,022 | n/a |
| 22 | 0.0253 | 0.644 | 0.33 | 642 | n/a |
| 24 | 0.0201 | 0.511 | 0.20 | 404 | n/a |
| 26 | 0.0159 | 0.405 | 0.13 | 254 | n/a |
| 28 | 0.0126 | 0.321 | 0.08 | 160 | n/a |
| 30 | 0.0100 | 0.255 | 0.05 | 101 | n/a |
14 AWG copper is limited to 15 A, 12 AWG to 20 A and 10 AWG to 30 A, and 12 and 10 AWG aluminum to 15 A and 25 A, by the overcurrent rules in NEC 240.4(D), even where the ampacity table lists more.
Sizes smaller than 14 AWG are not listed in Table 310.16, which covers building wire. They are used for low-voltage, control and electronic wiring.
How wire gauge works
Gauge numbers run backwards: 4 AWG is much thicker than 14 AWG. Two rules of thumb help you check any table:
- Every 6 gauge numbers, the diameter halves. 12 AWG is 0.0808 in and 18 AWG is 0.0403 in.
- Every 3 gauge numbers, the cross-section area roughly doubles or halves, so 10 AWG has about twice the copper of 13 AWG and half of 7 AWG.
Sizes larger than 4/0 (pronounced "four-aught") switch to kcmil, thousands of circular mils, starting at 250 kcmil. A circular mil is the area of a circle one thousandth of an inch across.
Which gauge for which job?
| Gauge | Typical use | Copper limit |
|---|---|---|
| 14 AWG | Lighting and 15 A receptacle circuits | 15 A |
| 12 AWG | 20 A circuits: kitchen, bath, garage, general receptacles | 20 A |
| 10 AWG | 30 A circuits: dryers, water heaters, small AC units | 30 A |
| 8 AWG | 40 to 50 A circuits: ranges, EV chargers, large AC | 50 A at 75°C |
| 6 AWG | 50 to 60 A: ranges, sub panels, hot tubs | 65 A at 75°C |
| 4 AWG | 60 to 85 A: sub panels, 100 A dwelling service | 85 A at 75°C |
These are minimums for ampacity only. Long runs need a larger wire to keep voltage drop in check, and bundling or hot locations cut the ampacity. See the breaker to wire size chart for the full list by breaker rating and the amps per wire size table for every gauge in all three temperature columns.
Solid, stranded and the metric sizes
Solid wire is one piece of copper and is common in house wiring up to 10 AWG. Stranded wire is many thin strands, more flexible and standard above 8 AWG and for cords. Stranded wire of the same gauge has the same copper area but a slightly larger overall diameter. Metric cable is sold by area: use the AWG to mm chart to convert.
Frequently asked questions
What is the thickest wire gauge?
In the AWG system, 4/0 (0000) is the thickest named gauge at 0.46 inches, or 11.7 mm. Larger conductors are sold in kcmil sizes such as 250 and 500 kcmil.
Is a lower gauge number thicker?
Yes. A 10 gauge wire is thicker than a 14 gauge wire and carries more current.
What gauge wire do I need for 20 amps?
12 AWG copper. 14 AWG is limited to 15 amps.
What is the difference between AWG and SWG?
AWG is the American standard. SWG, the British Standard Wire Gauge, is an older system with different diameters for the same number, so do not use the two interchangeably.