32
NEC Wire Gauge Chart
Allowable Ampacities of Insulated Conductors Rated 0 – 2000 Volts, 60° to 90°C (140° to 194°F), not more than three
conductors in Raceway or Cable or Earth (Directly Buried), Based on Ambient Temperature of 30°C (86°F)
*Unless otherwise specifically permitted elsewhere in this Code the overcurrent protection for conductor types marked with
an asterisk shall not exceed 15 amperes for No.14, 20 amperes for No.12, and 30 amperes for No.10 copper; or 15
amperes for No.12 and 25 amperes No. 10 aluminum and copper-clad aluminum after any correction factors for ambient
temperature and number of conductors have been applied.
Reprinted with permission from NFPA 70-1996, the National Electrical Code ®, Copyright 1995, National Fire Protection
Association, Quincy, MA 02269. This reprinted material is not the complete and official position of the National Fire
Protection Association on the referenced subject which is represented only by the standard in its entirety.
Size Temperature Rating of Conductor Size
60 C° (140°F) 75°C (167°F) 90°C (194°F) 60°C (140°F) 75°C (167°F) 90°C (194°F)
Types: TW*, UF* Types: FEPW*,
RH*, RHW*,
THHW*, THW*,
THWN*, XHHW*,
USE*, ZW*
Types: TA, TBS,
SA, SIS, FEP*,
FEPB*, MI, RHH*,
RHW-2, THHN*,
THHW*, THW-2,
THWN-2, USE-2,
XHH, XHHW*,
XHHW-2, ZW-2
Types: TW*, UF* Types: RH*,
RHW*, THHW*,
THW*, THWN*,
XHHW*, USE*
Types: TA, TBS,
SA, SIS, THHN*,
THHW*, THW-2,
THWN-2, RHH*,
RHW-2, USE-2,
XHH, XHHW*,
XHHW-2, ZW-2
AWG kcmll
Copper Aluminum or Copper-Clad Aluminum
AWG kcmll
18 - - 14 - - - -
16 - - 18 - - - -
14 20* 20* 25* - - - -
12 25* 25* 30* 20* 20* 25* 12
10 30 35* 40* 25 30* 35* 10
8 40 50 55 30 40 45 8
6 55 65 75 40 50 60 6
4 70 85 95 55 65 75 4
3 85 100 110 65 75 85 3
2 95 115 130 75 90 100 2
1 110 130 150 85 100 115 1
1/0 125 150 170 100 120 135 1/0
2/0 145 175 195 115 135 150 2/0
3/0 165 200 225 130 155 175 3/0
4/0 195 230 260 150 180 205 4/0
250 215 255 290 170 205 230 250
300 240 285 320 190 230 255 300
350 260 310 350 210 250 280 350
400 280 335 280 225 270 305 400
500 320 380 430 260 310 350 500
600 355 420 475 285 340 385 600
700 385 460 520 310 275 420 700
750 400 475 535 320 385 435 750
800 410 490 555 330 395 450 800
900 435 520 585 355 425 480 900
1000 455 545 615 375 445 500 1000
1250 495 590 665 405 485 545 1250
1500 520 625 705 435 520 585 1500
1750 545 650 735 455 545 615 1750
2000 560 665 750 470 560 630 2000
CORRECTION FACTORS
Ambient Temp.
°C For ambient temperatures other than 30° (86° F), multiply the allowable ampacities shown above by the appropriate factor shown
below. Ambient Temp. °C
21-25 1.08 1.05 1.04 1.08 1.05 1.04 70-77
26-30 1.00 1.00 1.00 1.00 1.00 1.00 78-86
31-35 .91 .94 .96 .91 .94 .96 87-95
36-40 .82 .88 .91 .82 .88 .91 96-104
41-45 .71 .82 .87 .71 .82 .87 105-113
46-50 .58 .75 .82 .58 .75 .82 114-122
51-55 .41 .67 .76 .41 .67 .76 123-131
56-60 -.58 .71 -.58 .71 132-140
61-70 -.33 .58 -.33 .58 141-158
71-80 - - .41 - - .41 159-176