Wire Properties
AWG conductor physical properties, resistance values, and insulation type ratings.
3 reference items · 2 sections
AWG Conductor Properties
Copper Conductor Properties
| AWG/kcmil | Area (cmil) | Diameter (in) | Ω/1000ft @75°C | Weight lb/1000ft |
|---|---|---|---|---|
| 18 | 1,620 | 0.0403 | 7.77 | 4.92 |
| 16 | 2,580 | 0.0508 | 4.89 | 7.81 |
| 14 | 4,110 | 0.0641 | 3.07 | 12.4 |
| 12 | 6,530 | 0.0808 | 1.93 | 19.8 |
| 10 | 10,380 | 0.1019 | 1.21 | 31.4 |
| 8 | 16,510 | 0.1285 | 0.764 | 50.0 |
| 6 | 26,240 | 0.162 | 0.491 | 79.4 |
| 4 | 41,740 | 0.204 | 0.308 | 126 |
| 3 | 52,620 | 0.229 | 0.245 | 159 |
| 2 | 66,360 | 0.258 | 0.194 | 200 |
| 1 | 83,690 | 0.289 | 0.154 | 253 |
| 1/0 | 105,600 | 0.325 | 0.122 | 319 |
| 2/0 | 133,100 | 0.365 | 0.0967 | 402 |
| 3/0 | 167,800 | 0.410 | 0.0766 | 507 |
| 4/0 | 211,600 | 0.460 | 0.0608 | 639 |
| 250 | 250,000 | 0.500 | 0.0515 | 756 |
| 300 | 300,000 | 0.548 | 0.0429 | 907 |
| 350 | 350,000 | 0.592 | 0.0367 | 1,058 |
| 400 | 400,000 | 0.632 | 0.0321 | 1,209 |
| 500 | 500,000 | 0.707 | 0.0258 | 1,511 |
| 600 | 600,000 | 0.775 | 0.0214 | 1,814 |
| 750 | 750,000 | 0.866 | 0.0171 | 2,267 |
| 1000 | 1,000,000 | 1.000 | 0.0129 | 3,023 |
1.DC resistance at 75°C for stranded, uncoated copper conductors
2.Solid conductor resistance is slightly lower (e.g., 14 AWG solid ≈ 3.14 Ω/1000ft)
3.Circular mil (cmil) = diameter in mils squared
4.1 kcmil = 1,000 circular mils
Aluminum Conductor Properties
| AWG/kcmil | Area (cmil) | Ω/1000ft @75°C | Weight lb/1000ft |
|---|---|---|---|
| 12 | 6,530 | 3.18 | 6.03 |
| 10 | 10,380 | 2.00 | 9.58 |
| 8 | 16,510 | 1.26 | 15.2 |
| 6 | 26,240 | 0.808 | 24.2 |
| 4 | 41,740 | 0.508 | 38.4 |
| 3 | 52,620 | 0.403 | 48.4 |
| 2 | 66,360 | 0.319 | 61.0 |
| 1 | 83,690 | 0.253 | 77.0 |
| 1/0 | 105,600 | 0.201 | 97.0 |
| 2/0 | 133,100 | 0.159 | 122 |
| 3/0 | 167,800 | 0.126 | 154 |
| 4/0 | 211,600 | 0.100 | 194 |
| 250 | 250,000 | 0.0847 | 230 |
| 300 | 300,000 | 0.0707 | 276 |
| 350 | 350,000 | 0.0605 | 322 |
| 400 | 400,000 | 0.0529 | 368 |
| 500 | 500,000 | 0.0424 | 460 |
| 750 | 750,000 | 0.0282 | 690 |
| 1000 | 1,000,000 | 0.0212 | 921 |
1.DC resistance at 75°C for stranded conductors
2.Aluminum is approximately 61% the conductivity of copper
3.Aluminum conductor is roughly 1/3 the weight of copper for same size
Conductor Insulation Types
Conductor Insulation Types & Temperature Ratings
| Type | Temp Rating | Application | Outer Covering |
|---|---|---|---|
| TW | 60°C | Dry & wet locations | None |
| THW | 75°C | Dry & wet locations | None |
| THWN | 75°C | Dry & wet locations | Nylon jacket |
| RHW | 75°C | Dry & wet locations | Moisture-resistant |
| XHHW | 75°C wet/90°C dry | Dry & wet locations | None |
| THHN | 90°C dry only | Dry locations only | Nylon jacket |
| THWN-2 | 90°C dry & wet | Dry & wet locations | Nylon jacket |
| XHHW-2 | 90°C dry & wet | Dry & wet locations | None |
| RHH | 90°C dry only | Dry locations only | Moisture-resistant |
| USE | 75°C | Underground service entrance | Moisture-resistant |
| USE-2 | 90°C | Underground service entrance | Moisture-resistant |
1.THHN/THWN-2 is the most commonly used building wire
2.90°C ampacity can be used for derating, but final ampacity limited to termination temp (usually 75°C)
3.Wet locations: conduit below grade, exterior, or areas subject to saturation
Common Cable/Wiring Methods
| Type | Conductor Temp | Description |
|---|---|---|
| NM-B | 90°C* | Non-metallic sheath (Romex) — dry locations |
| UF-B | 90°C* | Underground feeder — direct burial rated |
| MC | Per conductor | Metal-clad cable — various locations |
| AC | Per conductor | Armored cable (BX) — dry locations |
| MI | 250°C | Mineral insulated — special/hazardous applications |
1.* NM-B and UF-B conductors are rated 90°C, but ampacity is limited to the 60°C column per NEC 334.80 and 340.80
2.Cable types are wiring methods (NEC Articles 320-340), not insulation designations
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