Convert wire sizes between AWG and mm2. Pick an AWG number to see its area and diameter, or enter an area in mm2 to find the nearest AWG size.
AWG sizes are standard sizes for solid wire. Stranded cables of the same AWG have a slightly larger overall diameter. Current ratings differ between AWG and mm2 standards, so check ratings separately.
Formulas and assumptions
- Diameter (mm): 0.127 times 92 raised to the power ((36 minus AWG number) divided by 39)
- Area (mm2): pi divided by 4, times diameter squared
- Sizes larger than 1 AWG: 1/0 is AWG 0, 2/0 is AWG minus 1, 3/0 is minus 2 and 4/0 is minus 3
- Circular mils: mm2 times about 1973.5
Example
12 AWG has a diameter of 2.053 mm and an area of 3.31 mm2. Going the other way, 6 mm2 is closest to 9 AWG (6.63 mm2).
Frequently asked questions
What is AWG?
American Wire Gauge is a standard that sets wire diameter by a number. A higher number means a thinner wire, and every 3 gauge steps roughly halves the area.
What mm2 is 12 AWG?
About 3.31 mm2, with a diameter of 2.05 mm. A common metric size close to it is 4 mm2 and sometimes 2.5 mm2.
Can I replace AWG wire with the nearest mm2 size?
Choose the metric size that is equal or larger in area, and check the current rating, insulation and voltage drop separately.
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