AWG Wire Size Chart

This chart lists resistance and ampacity for copper and aluminum conductors from 14 AWG through 500 kcmil. Resistance values are approximate at 75°C from NEC Chapter 9, Table 9. Ampacity values are from NEC Table 310.16 (up to 3 current-carrying conductors in raceway, 30°C ambient). Always verify with the current edition of the NEC for your application.

Resistance (Approximate DC at 75°C)

Gauge	Copper (ohms / 1000 ft)	Aluminum (ohms / 1000 ft)
14 AWG	3.14	5.17
12 AWG	1.98	3.25
10 AWG	1.24	2.04
8 AWG	0.778	1.28
6 AWG	0.491	0.808
4 AWG	0.308	0.508
3 AWG	0.245	0.403
2 AWG	0.194	0.319
1 AWG	0.154	0.253
1/0 AWG	0.122	0.201
2/0 AWG	0.0967	0.159
3/0 AWG	0.0766	0.126
4/0 AWG	0.0608	0.1
250 kcmil	0.0515	0.0847
300 kcmil	0.0429	0.0707
350 kcmil	0.0367	0.0605
400 kcmil	0.0321	0.0529
500 kcmil	0.0258	0.0424
600 kcmil	0.0214	0.0353

Values are approximate. Actual resistance depends on stranding, temperature, and manufacturer. Source: NEC Chapter 9, Table 9 (approx.).

Ampacity (Copper, NEC Table 310.16)

Values assume up to 3 current-carrying conductors in raceway or cable, 75°C terminations, 30°C ambient. Derate for higher ambient or more conductors in conduit.

Gauge	60°C	75°C	90°C	Al 75°C	Al 90°C
14 AWG	15	20	25	-	-
12 AWG	20	25	30	25	30
10 AWG	30	35	40	30	35
8 AWG	40	50	55	40	45
6 AWG	55	65	75	50	60
4 AWG	70	85	95	65	75
3 AWG	85	100	110	75	85
2 AWG	95	115	130	90	100
1 AWG	110	130	150	100	115
1/0 AWG	125	150	170	120	135
2/0 AWG	145	175	195	135	150
3/0 AWG	165	200	225	155	175
4/0 AWG	195	230	260	180	205
250 kcmil	215	255	290	205	230
300 kcmil	240	285	320	230	255
350 kcmil	260	310	350	250	280
400 kcmil	280	335	380	270	305
500 kcmil	320	380	430	310	350

Approximate values from NEC Table 310.16. Verify with the current edition of the NEC.