10 Wire Ampacity & Specifications
NEC ampacity, resistance and typical uses for 10 copper and aluminum wire.
Calculations are built on the 2023 National Electrical Code (NEC) and cross-checked against the published code tables. How we verify. Last reviewed June 2026.
Copper 75°C
35A
Copper 90°C
40A
Aluminum 75°C
30A
Typical breaker
30A
10 Wire Specifications
| Ampacity — Copper (60 / 75 / 90°C) | 30 / 35 / 40 A |
| Ampacity — Aluminum (60 / 75 / 90°C) | 25 / 30 / 35 A |
| Cross-section | 10,380 circular mils |
| DC resistance — Copper | 1.21 Ω / 1000 ft |
| DC resistance — Aluminum | 2 Ω / 1000 ft |
| Typical voltage drop (240V) | 1.5% at 50 ft · 3.0% at 100 ft (at 30A) |
Common Uses for 10 Wire
- 30A circuits — dryers, water heaters, small AC, 30A RV
- Window AC and electric water heaters
Ampacities are from NEC Table 310.16. 14, 12 and 10 AWG are limited to 15A, 20A and 30A overcurrent protection (240.4(D)). Terminations rated 60°C or 75°C usually cap the usable ampacity below the 90°C value.
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