18 AWG wire specifications: 1.0237 mm diameter, 0.823 mm² area, 7A ampacity (copper, 75°C). Resistance, weight, and common uses.
| Diameter | 1.0237 mm · 0.040303" · 40.3 mils |
| Cross-sectional area | 0.823 mm² · 1,624 circular mils |
| Resistance (copper, 20°C) | 20.9466 Ω/km · 6.3845 Ω/1000ft |
| Resistance (aluminum, 20°C) | 32.1974 Ω/km · 9.8138 Ω/1000ft |
| Ampacity — copper 60°C | — A |
| Ampacity — copper 75°C | 7 A |
| Ampacity — copper 90°C | 14 A |
| Ampacity — aluminum 75°C | — A |
| Weight (copper) | 7.374 kg/km · 4.955 lbs/1000ft |
| Weight (aluminum) | 2.222 kg/km · 1.493 lbs/1000ft |
| Closest metric size | 0.8 mm² |
| Skin depth at 60 Hz | 8.531 mm |
| Type | Temperature | Description |
|---|---|---|
| THHN/THWN-2 | 90°C dry / 75°C wet | Building wire |
| NM-B (Romex) | 90°C | Residential cable |
| MTW | 60/90°C | Machine tool wire |
| TFFN | 90°C | Fixture wire |