Wire Gauge Chart: AWG to Amps & mm² Table
AWG Wire Gauge Chart
| AWG | Diameter (mm) | Area (mm²) | Amps (Copper, 60°C) | Amps (Aluminum, 60°C) | Common Use |
|---|---|---|---|---|---|
| 14 | 1.63 | 2.08 | 15 | — | Lighting circuits |
| 12 | 2.05 | 3.31 | 20 | 15 | General outlets |
| 10 | 2.59 | 5.26 | 30 | 25 | Appliances, AC |
| 8 | 3.26 | 8.37 | 40 | 30 | Electric range, dryer |
| 6 | 4.11 | 13.3 | 55 | 40 | Sub-panels, large AC |
| 4 | 5.19 | 21.2 | 70 | 55 | Service entrance |
| 2 | 6.54 | 33.6 | 95 | 75 | Service entrance |
| 1/0 | 8.25 | 53.5 | 125 | 100 | 200A service |
| 2/0 | 9.27 | 67.4 | 145 | 115 | 200A service |
NEC Table 310.16 ampacity values for not more than 3 current-carrying conductors in raceway or cable. For 75°C rated terminations, use the 75°C column (higher ampacity).
Copper vs Aluminum Wire
Copper is the standard for branch circuits (15–50A). Aluminum is used for service entrance and large feeders (100A+) due to lower cost. Key differences:
- Ampacity: Aluminum carries ~75% of copper's current at the same gauge
- Cost: Aluminum is 40–60% cheaper per foot for large sizes
- Weight: Aluminum is 50% lighter
- Connections: Aluminum requires anti-oxidant compound and rated connectors (CO/ALR)
Frequently Asked Questions
What AWG wire do I need for 20 amps?
12 AWG copper wire is rated for 20 amps (NEC Table 310.16, 60°C column). For continuous loads (3+ hours), use 10 AWG (30 amp rated) as NEC requires 125% of continuous load.
What is the difference between AWG and mm²?
AWG (American Wire Gauge) is the US standard; mm² is the metric cross-sectional area. Lower AWG = thicker wire. 14 AWG = 2.08 mm², 12 AWG = 3.31 mm², 10 AWG = 5.26 mm², 8 AWG = 8.37 mm².
How do I read a wire gauge chart?
Find your required ampacity in the chart, then match it to the wire size. Always check the conductor material (copper vs aluminum) and temperature rating (60°C, 75°C, or 90°C). Copper handles more current than aluminum at the same gauge.