6 AWG Wire — Ampacity, Conduit Fill & Dimensions

Everything the code tables say about 6 AWG conductors on one page: ampacity by temperature rating, breaker limits, conduit fill, physical size, resistance and voltage-drop distances.

6 AWG copper carries 55 A at 60°C, 65 A at 75°C and 75 A at 90°C.

Copper, 75°C
65 A
Aluminum, 75°C
50 A
Conductor area
26,240 cmil · 13.3 mm²
THHN diameter
0.254 in
DC resistance, Cu
0.491 Ω/1000 ft

6 AWG ampacity

6 AWG ampacity (amps), 30°C ambient, not more than three current-carrying conductors
CopperAluminum
Installation60°C75°C90°C60°C75°C90°C
Raceway, cable or earth — Table 310.16556575405055
Single conductor in free air — Table 310.178095105607585

Typical use: 50–65 A circuits: 48 A EV chargers, large ranges, hot tubs and 60 A sub-panels.

Use the column that matches the lowest temperature rating in the circuit — usually the 75°C terminations on breakers and lugs. The 90°C column is a starting point for derating, not a rating you can load the wire to. NM-B (Romex) cable is always limited to the 60°C column.

As a copper equipment grounding conductor, 6 AWG is the minimum for circuits protected at up to 200 A; in aluminum, up to 100 A. See the grounding conductor table.

6 AWG conduit fill

Mixing sizes or using another insulation? Use the conduit fill calculator.

6 AWG dimensions

6 AWG overall diameter and area including insulation
InsulationDiameter (in)Diameter (mm)Area (in²)Area (mm²)
THHN, THWN, THWN-20.2546.450.050732.7
XHHW, XHHW-2, XHH0.2746.960.059038.1
TW, THW, THHW, THW-20.3047.720.072646.8
RHH, RHW, RHW-2 (with outer covering)0.3649.250.104167.2

6 AWG voltage drop

Maximum one-way length of 6 AWG copper for 3% voltage drop
Load120 V 1-phase240 V 1-phase208 V 3-phase480 V 3-phase
20 A183 ft366 ft366 ft846 ft
30 A122 ft244 ft244 ft564 ft
40 A91 ft183 ft183 ft423 ft
50 A73 ft146 ft146 ft338 ft
60 A61 ft122 ft122 ft282 ft

Based on 0.491 Ω per 1000 ft for stranded copper at 75°C (0.808 Ω for aluminum). For other loads and lengths use the voltage drop calculator.

All wire sizes

Frequently asked questions

How many amps can 6 AWG wire carry?

6 AWG copper is rated 55 A at 60°C, 65 A at 75°C and 75 A at 90°C when run in conduit or cable. Aluminum is rated 40, 50 and 55 A. Most terminations are rated 75°C, so the 75°C figure is the one normally used.

What size conduit do I need for 6 AWG wire?

Three 6 AWG THHN conductors need at least 3/4-inch EMT. 3/4-inch EMT holds 4.

What is the diameter of 6 AWG wire?

The bare conductor is 26,240 circular mils (13.3 mm²). With THHN insulation the overall diameter is about 0.254 in (6.45 mm) and the area is 0.0507 in², which is the figure used for conduit fill.

How far can I run 6 AWG wire?

For a 3% voltage drop on a 240 V single-phase circuit carrying 60 A, about 122 feet one way in copper. Halve that at 120 V. Lighter loads go proportionally farther.

NECTables.com is an independent reference and is not affiliated with, endorsed by, or a substitute for the National Fire Protection Association (NFPA). NEC® and National Electrical Code® are registered trademarks of the NFPA. Values shown are commonly published engineering data and independent calculations based on the methods of NFPA 70; they are not a reproduction of the Code. Always confirm against the edition adopted in your jurisdiction, including local amendments, and consult a licensed electrician or engineer before doing electrical work.