WIRE GAUGE CHARTS
12 wire in mm
Thickness: 2.05 mm diameter (0.081 inches), 3.31 mm² cross-section of solid copper.
Specifications
- Diameter
- 2.05 mm
- Diameter (imperial)
- 0.081 in
- Cross-section
- 3.31 mm²
- Area (kcmil)
- 6.5
- Copper resistance
- 1.588 Ω/1000 ft
- Copper resistance (metric)
- 5.21 Ω/km
- Copper weight
- 29.6 g/m
- Ampacity (NEC 75 °C)
- 25 A
Nearest metric sizes
3.31 mm² does not match a standard metric cable size exactly. The closest conventional cross-sections are1.5 mm², 2.5 mm² and 4 mm²— engineers round this wire up (larger cross-section) for ampacity, or accept the raw equality for signal work.
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Frequently asked questions
Is 12 gauge wire thick or thin?
12 gauge wire is 2.05 mm in diameter. On the AWG scale a lower number means a thicker wire, so 12 AWG sits in the mid-power range used for appliances and small feeders.
How many amps can 12 gauge wire carry?
NEC Table 310.16 rates 12 AWG copper at 25 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 12 wire in millimeters?
12 gauge wire is 2.05 mm (0.081 in) in diameter, with a solid-conductor cross-section of 3.31 mm².