AWG Wire Size Chart: Circular Mils, Resistance & Ampacity

American Wire Gauge geometry and resistance — circular mils, ohms per 1,000 ft for copper and aluminum, and the NEC 310.16 ampacity at 75°C.

AWG	Circular Mils	Ω / 1,000 ft (Cu)	Ω / 1,000 ft (Al)	Ampacity 75°C Cu
14 AWG	4,107	3.0700	5.0453	20 A
12 AWG	6,530	1.9300	3.1718	25 A
10 AWG	10,380	1.2100	1.9885	35 A
8 AWG	16,510	0.7640	1.2556	50 A
6 AWG	26,240	0.4910	0.8069	65 A
4 AWG	41,740	0.3080	0.5062	85 A
3 AWG	52,620	0.2450	0.4026	100 A
2 AWG	66,360	0.1940	0.3188	115 A
1 AWG	83,690	0.1540	0.2531	130 A
1/0 AWG	105,600	0.1220	0.2005	150 A
2/0 AWG	133,100	0.0967	0.1589	175 A
3/0 AWG	167,800	0.0766	0.1259	200 A
4/0 AWG	211,600	0.0608	0.0999	230 A

Sources: NEC Chapter 9 Table 8 (conductor resistance), NEC 310.16 (ampacity), NEC Chapter 9 Tables 1/4/5 (conduit areas & THHN), ASTM B258 (AWG geometry), NREL (peak sun hours) · All sources