NEC Article 310: Table 310.16 is THE ampacity table. Copper at 60C/75C/90C column (use connector rating, not conductor). 14 AWG: 15/15/15A. 12 AWG: 20/20/25A. 10 AWG: 30/30/35A. 8 AWG: 40/50/55A. 6 AWG: 55/65/75A. 4 AWG: 70/85/95A. 3 AWG: 85/100/115A. 2 AWG: 95/115/130A. 1 AWG: 110/130/145A. 1/0: 125/150/170A. 2/0: 145/175/195A. 310.15(B)(3)(a) adjustment for >3 current-carrying conductors: 4-6 = 80%, 7-9 = 70%, 10-20 = 50%. 310.15(B)(2) ambient temperature correction per Table 310.15(B)(2)(a). Conductor types: THHN/THWN-2 (most common, 90C dry/wet), XHHW-2, USE-2 (underground).