Ampacity is the current a wire can safely carry. This chart shows copper wire at the 60°C rating common in homes, with typical uses. Aluminum carries less and must be sized up.
| Wire (AWG) | Ampacity | Typical use |
|---|---|---|
| 14 | 15 A | Lighting circuits |
| 12 | 20 A | Outlets, kitchen circuits |
| 10 | 30 A | Dryer, water heater |
| 8 | 40 A | Range, sub-feeds |
| 6 | 55 A | Large appliances |
| 4 | 70 A | Sub-panels |
| 2 | 95 A | Service / sub-panel |
| 1/0 | 125 A | Service entrance |
Derate for conditions. Bundling wires, high ambient temperature, and long runs all reduce safe ampacity. Always follow the NEC and your local code — this chart is a planning reference.
FAQ
Does wire ampacity change based on installation conditions? Yes. Ampacity ratings assume specific conditions like ambient temperature and number of current-carrying conductors bundled together, so wires run in hot attics or bundled with several others often need to be derated below their base ampacity rating.
See the Breaker Size Chart and AWG Wire Gauge Chart.
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