12 AWG Wire Ampacity & Specifications
12 AWG copper wire carries 25A at 75°C (NEC Table 310.16), or 20A for aluminum; copper is typically protected by a 20A breaker.
Calculations are built on the 2023 National Electrical Code (NEC) and cross-checked against the published code tables. How we verify. Last updated June 2026.
12 AWG wire has an ampacity of 25A at 75°C for copper and 20A for aluminum (NEC Table 310.16). Its 60°C and 90°C copper ratings are 20A and 30A. Copper 12 AWG is commonly protected by a 20A breaker, since 12 AWG is limited to 20A overcurrent protection by NEC 240.4(D).
Copper 75°C
25A
Copper 90°C
30A
Aluminum 75°C
20A
Copper breaker (75°C)
20A
12 AWG Wire Specifications
| Ampacity — Copper (60 / 75 / 90°C) | 20 / 25 / 30 A |
| Ampacity — Aluminum (60 / 75 / 90°C) | 15 / 20 / 25 A |
| Cross-section | 6,530 circular mils |
| DC resistance — Copper | 1.93 Ω / 1000 ft |
| DC resistance — Aluminum | 3.18 Ω / 1000 ft |
| Typical voltage drop (240V) | 1.6% at 50 ft · 3.2% at 100 ft (at 20A) |
Common Uses for 12 AWG Wire
- 20A kitchen, bath and garage receptacle circuits
- Most home 20A branch circuits
Ampacities are from NEC Table 310.16. Copper 14, 12 and 10 AWG are limited to 15A, 20A and 30A overcurrent protection, aluminum 12 and 10 AWG to 15A and 25A (240.4(D)). Terminations rated 60°C or 75°C usually cap the usable ampacity below the 90°C value.
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