NEC Table 310.16 Ampacities of Insulated Conductors with Not More Than Three Current-Carrying Conductors in Raceway, Cable, or Earth (Directly Buried)

Table 310.16 is one of the most commonly used tables in the National Electrical Code. The reason is the inherent practicality and breadth of installations covered by “…Insulated Conductors with Not More Than Three Current-Carrying Conductors in Raceway, Cable, or Earth (Directly Buried)”. Note: a neutral is a current-carrying conductor while the grounding conductor(s) are not.

Pay close attention to the table notes, they are critical to proper application of Table 310.16.

NEC Table 310.16 Copper

Size AWG or kcmil60°C (140°F)75°C (167°F)90°C (194°F) 
Types TW, UFTypes RHW, THHW, THW, THWN, XHHW, XHWN, USE, ZWTypes TBS, SA, SIS, FEP, FEPB, MI, PFA, RHH, RHW-2, THHN, THHW, THW-2, THWN-2, USE-2, XHH, XHHW, XHHW-2, XHWN, XHWN-2, XHHN, Z, ZW-2
18*14
16*18
14*152025
12*202530
10*303540
8405055
6556575
4708595
385100115
295115130
1110130145
1/0125150170
2/0145175195
3/0165200225
4/0195230260
250215255290
300240285320
350260310350
400280335380
500320380430
600350420475
700385460520
750400475535
800410490555
900435520585
1000455545615
1250495590665
1500525625705
1750545650735
2000555665750

NEC Table 310.16 Aluminum or Copper-Clad Aluminum

Size AWG or kcmil60°C (140°F)75°C (167°F)90°C (194°F) 
Types TW, UFTypes RHW, THHW, THW, THWN, XHHW, XHWN, USETypes TBS, SA, SIS, THHN, THHW, THW-2, THWN-2, RHH, RHW-2, USE-2, XHH, XHHW, XHHW-2, XHWN, XHWN-2, XHHN
12*152025
10*253035
8354045
6405055
4556575
3657585
27590100
185100115
1/0100120135
2/0115135150
3/0130155175
4/0150180205
250170205230
300195230260
350210250280
400225270305
500260310350
600285340385
700315375425
750320385435
800330395445
900355425480
1000375445500
1250405485545
1500435520585
1750455545615
2000470560630

Table Notes:

  1. Section 310.15(B) shall be referenced for ampacity correction factors where the ambient temperature is other than 30°C (86°F).
  2. Section 310.15(C)(1) shall be referenced for more than three current-carrying conductors.
  3. Section 310.16 shall be referenced for conditions of use.
  4. * Section 240.4(D) shall be referenced for conductor overcurrent protection limitations, except as modified elsewhere in the Code.

Source: NFPA 70