AWG wire size chart (NEC Chapter 9, Table 8)
Every three AWG sizes the area of a wire doubles: 12 AWG is 6,530 circular mils and 9 AWG would be about 13,090. Above 4/0 AWG, sizes are named by area in thousands of circular mils (kcmil), so 250 kcmil is 250,000 circular mils.
| Size | Circular mils | Area (mm2) | Copper, ohms per 1,000 ft | Aluminum, ohms per 1,000 ft |
|---|---|---|---|---|
| 18 AWG | 1,620 | 0.82 | 7.95 | 13.1 |
| 16 AWG | 2,580 | 1.31 | 4.99 | 8.21 |
| 14 AWG | 4,110 | 2.08 | 3.14 | 5.17 |
| 12 AWG | 6,530 | 3.31 | 1.98 | 3.25 |
| 10 AWG | 10,380 | 5.26 | 1.24 | 2.04 |
| 8 AWG | 16,510 | 8.37 | 0.778 | 1.28 |
| 6 AWG | 26,240 | 13.30 | 0.491 | 0.808 |
| 4 AWG | 41,740 | 21.15 | 0.308 | 0.508 |
| 3 AWG | 52,620 | 26.7 | 0.245 | 0.403 |
| 2 AWG | 66,360 | 33.6 | 0.194 | 0.319 |
| 1 AWG | 83,690 | 42.4 | 0.154 | 0.253 |
| 1/0 AWG | 105,600 | 53.5 | 0.122 | 0.201 |
| 2/0 AWG | 133,100 | 67.4 | 0.0967 | 0.159 |
| 3/0 AWG | 167,800 | 85.0 | 0.0766 | 0.126 |
| 4/0 AWG | 211,600 | 107.2 | 0.0608 | 0.1 |
| 250 kcmil | 250,000 | 126.7 | 0.0515 | 0.0847 |
| 300 kcmil | 300,000 | 152.0 | 0.0429 | 0.0707 |
| 350 kcmil | 350,000 | 177.3 | 0.0367 | 0.0605 |
| 400 kcmil | 400,000 | 202.7 | 0.0321 | 0.0529 |
| 500 kcmil | 500,000 | 253.3 | 0.0258 | 0.0424 |
| 600 kcmil | 600,000 | 304.0 | 0.0214 | 0.0353 |
| 700 kcmil | 700,000 | 354.7 | 0.0184 | 0.0303 |
| 750 kcmil | 750,000 | 380.0 | 0.0171 | 0.0282 |
| 800 kcmil | 800,000 | 405.4 | 0.0161 | 0.0265 |
| 900 kcmil | 900,000 | 456.0 | 0.0143 | 0.0235 |
| 1000 kcmil | 1,000,000 | 506.7 | 0.0129 | 0.0212 |
- Resistance is for stranded, uncoated conductors at 75 C, from NEC Chapter 9, Table 8. It is what the voltage drop calculator uses.
- Square millimeters are converted from circular mils (1 circular mil = 0.0005067 square millimeters) and rounded; they are not metric wire sizes.