Standard wire size for 30-amp circuits including electric dryers, water heaters, and window AC units.
| Wire Gauge | 10 AWG |
| Diameter (inches) | 0.1019 in |
| Diameter (mm) | 2.588 mm |
| Cross-sectional Area | 5.26 mm² (10,380 circular mils) |
| Copper Resistance | 3.277 Ω/1000ft (10.75 Ω/km) @ 20°C |
| Copper Ampacity (60°C) | 30A |
| Copper Ampacity (75°C) | 35A |
| Copper Ampacity (90°C) | 40A |
| Max Circuit Breaker | 30A (per NEC) |
240V electric dryers typically use 30A circuits with 10 AWG wire. Check if your dryer is 30A or 50A (larger dryers).
Most residential electric water heaters (40-50 gallon) require 30A circuits with 10/2 or 10/3 wire.
Large window air conditioners (10,000+ BTU) may require 30A circuits.
30A RV outlets (TT-30) for travel trailers and smaller motorhomes.
Heavy-duty workshop circuits for welders and large power tools.
120V plug-and-play hot tubs and some 240V small spas.
| Wire Type | Application | Notes |
|---|---|---|
| 10/2 NM-B | Water heaters, 240V appliances | Two conductors + ground, indoor only |
| 10/3 NM-B | Electric dryers, ranges (30A) | Three conductors + ground, for 120/240V |
| 10/2 UF-B | Outdoor/underground | Direct burial rated, wet locations |
| 10 AWG THHN | Conduit installations | Individual conductors in conduit |
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