AWG chart
12 AWG wire is 0.0808 in. (2.05 mm) across and has an area of 6,530 circular mils. Every three gauge numbers smaller, the area of an AWG wire roughly doubles.
| Size | Diameter, in. | Diameter, mm | Area, cmil | Area, mm² | Copper, Ω per 1,000 ft | Aluminum, Ω per 1,000 ft |
|---|---|---|---|---|---|---|
| 18 AWG | 0.0403 | 1.02 | 1,620 | 0.823 | 7.9630 | — |
| 16 AWG | 0.0508 | 1.29 | 2,580 | 1.31 | 5.0000 | — |
| 14 AWG | 0.0641 | 1.63 | 4,110 | 2.08 | 3.1387 | — |
| 12 AWG | 0.0808 | 2.05 | 6,530 | 3.31 | 1.9755 | 3.2466 |
| 10 AWG | 0.1019 | 2.59 | 10,380 | 5.26 | 1.2428 | 2.0424 |
| 8 AWG | 0.1285 | 3.26 | 16,510 | 8.37 | 0.7813 | 1.2841 |
| 6 AWG | 0.1620 | 4.12 | 26,240 | 13.3 | 0.4916 | 0.8079 |
| 4 AWG | 0.2043 | 5.19 | 41,740 | 21.2 | 0.3091 | 0.5079 |
| 3 AWG | 0.2294 | 5.83 | 52,620 | 26.7 | 0.2452 | 0.4029 |
| 2 AWG | 0.2576 | 6.54 | 66,360 | 33.6 | 0.1944 | 0.3195 |
| 1 AWG | 0.2893 | 7.35 | 83,690 | 42.4 | 0.1541 | 0.2533 |
| 1/0 AWG | 0.3249 | 8.25 | 105,600 | 53.5 | 0.1222 | 0.2008 |
| 2/0 AWG | 0.3648 | 9.27 | 133,100 | 67.4 | 0.0969 | 0.1593 |
| 3/0 AWG | 0.4096 | 10.40 | 167,800 | 85 | 0.0769 | 0.1263 |
| 4/0 AWG | 0.4600 | 11.68 | 211,600 | 107.2 | 0.0610 | 0.1002 |
| 250 kcmil | 0.5000 | 12.70 | 250,000 | 127 | 0.0516 | 0.0848 |
| 300 kcmil | 0.5477 | 13.91 | 300,000 | 152 | 0.0430 | 0.0707 |
| 350 kcmil | 0.5916 | 15.03 | 350,000 | 177 | 0.0369 | 0.0606 |
| 400 kcmil | 0.6325 | 16.06 | 400,000 | 203 | 0.0323 | 0.0530 |
| 500 kcmil | 0.7071 | 17.96 | 500,000 | 253 | 0.0258 | 0.0424 |
| 600 kcmil | 0.7746 | 19.67 | 600,000 | 304 | 0.0215 | 0.0353 |
How the AWG sizes are calculated
AWG diameters follow the formula d = 0.005 in. × 92^((36 − n) ÷ 39), where n is the gauge number and 1/0, 2/0, 3/0, 4/0 count as 0, −1, −2 and −3. Diameters are for a solid conductor; stranded wire of the same gauge is slightly larger. kcmil sizes are defined by area, and their diameter here is that of a solid conductor of the same area.
Resistance uses the same constants as the voltage-drop calculations on this site: 12.9 Ω·cmil/ft for copper and 21.2 for aluminum, which correspond to a conductor at operating temperature.