20 AWG (American Wire Gauge) wire specifications: 0.8118 mm diameter, 0.5176 mm² area. Resistance, weight, and common uses.
| Diameter | 0.8118 mm · 0.031961" · 31.96 mils |
| Cross-sectional area | 0.5176 mm² · 1,022 circular mils |
| Resistance (copper, 20°C) | 33.3063 Ω/km · 10.1518 Ω/1000ft |
| Resistance (aluminum, 20°C) | 54.6006 Ω/km · 16.6423 Ω/1000ft |
| Ampacity — copper 60°C | — A |
| Ampacity — copper 75°C | — A |
| Ampacity — copper 90°C | — A |
| Ampacity — aluminum 75°C | — A |
| Weight (copper) | 4.638 kg/km · 3.116 lbs/1000ft |
| Weight (aluminum) | 1.398 kg/km · 0.939 lbs/1000ft |
| Closest IEC 60228 size | 0.5 mm² |
| Skin depth at 60 Hz | 8.531 mm |
| Type | Temperature | Description |
|---|---|---|
| PVC | 60-105°C | General purpose insulation |
| Teflon (PTFE) | 200°C | High temperature applications |
| Silicone | 200°C | Flexible, high temperature |
| Enamel | 155-220°C | Magnet wire coating |
20 AWG copper is used for low-voltage electronics and thermostat wire. It is a low-voltage size and is not permitted for 120V building branch circuits. Diameter is 0.812 mm and cross-section 0.518 mm².
20 AWG is not listed in NEC Table 310.16, so it has no code ampacity for building wiring. Commonly cited guidance is about 11A for a single conductor in free air (chassis wiring) and about 1.5A when bundled for power transmission. In long low-voltage runs, voltage drop usually limits it first.