WIRE GAUGE CHARTS
3/0 wire in mm
Thickness: 10.40 mm diameter (0.410 inches), 85.03 mm² cross-section of solid copper.
Specifications
- Diameter
- 10.40 mm
- Diameter (imperial)
- 0.410 in
- Cross-section
- 85.03 mm²
- Area (kcmil)
- 167.8
- Copper resistance
- 0.062 Ω/1000 ft
- Copper resistance (metric)
- 0.20 Ω/km
- Copper weight
- 761.9 g/m
- Ampacity (NEC 75 °C)
- 200 A
Nearest metric sizes
85.03 mm² does not match a standard metric cable size exactly. The closest conventional cross-sections are70 mm², 95 mm² and 120 mm²— engineers round this wire up (larger cross-section) for ampacity, or accept the raw equality for signal work.
One gauge away:2/0 · thinner4/0 · thickerFull chart →
Frequently asked questions
Is 3/0 gauge wire thick or thin?
3/0 gauge wire is 10.40 mm in diameter. On the AWG scale a lower number means a thicker wire, so 3/0 AWG sits toward the thick end, where service and feeder wires live.
How many amps can 3/0 gauge wire carry?
NEC Table 310.16 rates 3/0 AWG copper at 200 A in the 75 °C column (see our amp chart for 60/75/90 °C ratings). Use the calculator to check voltage drop at your run length; long runs often force one size thicker.
What diameter is 3/0 wire in millimeters?
3/0 gauge wire is 10.40 mm (0.410 in) in diameter, with a solid-conductor cross-section of 85.03 mm².