Free-Air Ampacity (Table 310.17)

Ampacity for single conductors in free air - not in conduit or cable. Values are higher than Table 310.16 (in-raceway) because heat dissipates more freely.

Copper

Wire	60°C	75°C	90°C
14 AWG	25A	30A	35A
12 AWG	30A	35A	40A
10 AWG	40A	50A	55A
8 AWG	60A	70A	80A
6 AWG	80A	95A	105A
4 AWG	105A	125A	140A
3 AWG	120A	145A	165A
2 AWG	140A	170A	190A
1 AWG	165A	195A	220A
1/0 AWG	195A	230A	260A
2/0 AWG	225A	265A	300A
3/0 AWG	260A	310A	350A
4/0 AWG	300A	360A	405A
250 kcmil	340A	405A	455A
300 kcmil	375A	445A	500A
350 kcmil	420A	505A	570A
400 kcmil	455A	545A	615A
500 kcmil	515A	620A	700A
600 kcmil	575A	690A	780A
700 kcmil	630A	755A	850A
750 kcmil	655A	785A	885A

Aluminum

Wire	60°C	75°C	90°C
12 AWG	25A	30A	35A
10 AWG	35A	40A	45A
8 AWG	45A	55A	60A
6 AWG	60A	75A	85A
4 AWG	80A	100A	115A
3 AWG	95A	115A	130A
2 AWG	110A	135A	150A
1 AWG	130A	155A	175A
1/0 AWG	150A	180A	205A
2/0 AWG	175A	210A	235A
3/0 AWG	200A	240A	270A
4/0 AWG	235A	280A	315A

Back to in-raceway ampacity tables (Table 310.16)

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NEC 2023 references verified April 2026