Wire & voltage
AWG to mm² Calculator
AWG diameter follows the standard logarithmic gauge relationship, and area equals pi times diameter squared divided by four. Metric area can be compared with the nearest nominal AWG geometry.
Convert American Wire Gauge to diameter, cross-sectional area, and circular mils, or find the nearest AWG for a metric area.
Calculated result
Conductor geometry
Calculating…
Calculated locally in your browser
Planning math only. Verify equipment specifications and installation requirements separately.
What this calculator returns
Metric conductors are not exact ampacity equivalents. Use the nearest-size result as a geometry reference only.
Formula and variables
The calculation runs entirely in your browser. Static formulas, definitions, examples, and tables remain readable without JavaScript.
Diameter(in) = 0.005 × 92^((36 - n)/39); area = πd²/4; circular mils = diameter(mils)².
- Vdrop
- Voltage lost across the conductor path, in volts.
- I
- Current through the conductor, in amperes.
- R
- Electrical resistance of the modeled conductor path, in ohms.
- ρ
- Material resistivity at the modeled temperature, in ohm-metres.
- L
- Conductor length used by the selected path model.
- A
- Metal cross-sectional area of the conductor.
n is the AWG gauge number, with 0, 00, 000, and 0000 represented by indices 0 through -3.
Worked example
| Input | Value |
|---|---|
| Conversion direction | AWG to metric |
| AWG size | 12 AWG |
| Metric area | 2.5 mm² |
| Result | 12 AWG has a calculated diameter of about 2.053 mm and a cross-sectional area of about 3.309 mm². |
12 AWG has a calculated diameter of about 2.053 mm and a cross-sectional area of about 3.309 mm².
Reference table
| AWG | Cu 20°C Ω/1000 ft | Cu 75°C Ω/1000 ft | Al 20°C Ω/1000 ft | Al 75°C Ω/1000 ft | Cu 20°C Ω/km | Al 20°C Ω/km |
|---|---|---|---|---|---|---|
| 14 | 2.5254 | 3.0712 | 4.1400 | 5.0576 | 8.2853 | 13.5825 |
| 12 | 1.5882 | 1.9315 | 2.6036 | 3.1807 | 5.2107 | 8.5421 |
| 10 | 0.9988 | 1.2147 | 1.6374 | 2.0004 | 3.2770 | 5.3722 |
| 8 | 0.6282 | 0.7640 | 1.0298 | 1.2581 | 2.0609 | 3.3786 |
| 6 | 0.3951 | 0.4805 | 0.6476 | 0.7912 | 1.2961 | 2.1248 |
| 4 | 0.2485 | 0.3022 | 0.4073 | 0.4976 | 0.8152 | 1.3363 |
Frequently asked questions
Is this AWG conversion result code compliant?
No. PowerTotals performs transparent electrical math and planning estimates. Installation decisions must be checked against equipment documentation, the adopted code, and the authority having jurisdiction.
Are my inputs uploaded?
No. Calculations run locally in your browser, and analytics never receives raw electrical values.
Is 2.5 mm² exactly the same as 12 AWG?
No. The calculator shows geometric area and the nearest nominal AWG; standards and construction differ.
Assumptions and limitations
- Solid-wire nominal geometry is calculated from the AWG relationship.
- Stranding and insulation change physical outside diameter.
- No ampacity equivalence is claimed.
Method and sources
Read the calculation methodology, review the technical sources, or browse the reference table index. Last reviewed .