6 AWG Wire Size — Diameter, Ampacity & Resistance

Quick Reference — 6 AWG

Diameter: 0.1620″ (4.115 mm)
Area: 13.3 mm² (26240 cmil)
Resistance: 0.395 Ω/1000ft (Cu)
Ampacity (75°C): 65A

Common uses: Range/oven circuits, central AC, hot tub/spa wiring, subpanel feeders

Wire Properties

AWG Size 6 AWG
Diameter (inches) 0.1620″
Diameter (mm) 4.115 mm
Cross-sectional area 13.3 mm² (26240 circular mils)
Resistance — Copper 0.395 Ω per 1000 ft @ 20°C
Resistance — Aluminum 0.648 Ω per 1000 ft @ 20°C
Weight (copper) ~79.4 lb per 1000 ft

Ampacity (Current Carrying Capacity)

Per NEC Table 310.16 — Copper conductor, 3+ current-carrying conductors in raceway/cable:

Insulation Rating Ampacity
60°C (TW, UF) 55A
75°C (THW, THWN, XHHW) 65A
90°C (THHN, XHHW-2) 75A

Note: Actual ampacity may be reduced by ambient temperature corrections and conduit fill derating factors per NEC 310.15.

Voltage Drop Example

For a 15A load on 6 AWG copper wire, 100 ft one-way run (120V circuit):

Wire resistance: 0.395 Ω/1000ft × 200ft (round trip) ÷ 1000 = 0.0790 Ω

Voltage drop: 15A × 0.0790 Ω = 1.19V

Percent drop: 1.19V ÷ 120V = 1.0%

NEC recommends ≤3% voltage drop for branch circuits, ≤5% total (feeder + branch).

Nearby Sizes for Comparison

AWG Dia (in) Dia (mm) Area (mm²) Ω/1000ft Cu Ampacity 75°C
4 0.2043 5.189 21.2 0.249 85A
6 0.1620 4.115 13.3 0.395 65A
8 0.1285 3.264 8.37 0.628 50A

⚠️ AWG Sizing Reminder

  • In AWG, lower numbers = thicker wire. 4 AWG is much thicker than 14 AWG.
  • Each 3-gauge decrease doubles the cross-sectional area (e.g., 11 AWG ≈ 2× the area of 14 AWG).
  • Each 6-gauge decrease doubles the diameter.
  • Always follow local electrical codes — NEC values are minimum requirements.

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