AWG to mm² Converter 📏
Convert American Wire Gauge (AWG) to square millimeters (mm²) instantly. This AWG to mm² converter calculates wire diameter, cross-sectional area, and electrical resistance for copper conductors using the ASTM B258 standard.
Convert between American Wire Gauge and Metric area instantly.
| Typical Ampacity (75°C Copper) | 20 A |
|---|---|
| Copper Resistance | 5.21 Ω/km (1.59 Ω/1000ft) |
| Aluminum Resistance | 8.28 Ω/km (2.52 Ω/1000ft) |
| Conductor Bare Weight | Cu: 29.66 kg/km Al: 8.94 kg/km |
| Voltage Drop Ref. (10A over 30m / 100ft Round Trip) | 3.13 V |
| AWG | Area (mm²) | Ampacity | Cu Ω/km |
|---|
Free AWG to mm² Converter
Converting electrical wire sizes between the American Wire Gauge (AWG) standard and the international metric standard (mm²) is a daily necessity for engineers, electricians, and hobbyists. Our free converter provides exact cross-sectional area, diameters, circular mils (cmil), and physical resistance values for both copper and aluminum.
How to Use the Converter
- Select your conversion mode: Click the toggle at the top to choose between "AWG to mm²" (Forward) or "mm² to AWG" (Reverse).
- Input your values: Either select the AWG size from the dropdown, use the interactive thickness slider to visually dial in your wire size, or type in your target metric area.
- Review the Engineering Data: The tool instantly outputs exact diameter measurements, circular mils, bare conductor weight, and estimates for ampacity and standard voltage drop.
- Export your results: Use the "Copy Full Report" button at the bottom to instantly copy all input parameters, math outputs, and comparison charts to your clipboard for project documentation.
What is AWG Wire Gauge?
The American Wire Gauge (AWG) is a standardized logarithmic wire sizing system used primarily in North America. The system is counter-intuitive to beginners: the larger the AWG number, the smaller the wire thickness. For example, a 14 AWG wire is much thinner than a 4 AWG wire. For wires thicker than 1 AWG, the system uses zeros (e.g., 1/0, 2/0, 3/0, 4/0).
AWG vs Metric Wire Sizes
While the US uses the AWG scale, most of the rest of the world specifies wire by its exact physical cross-sectional area measured in square millimeters (mm²). Unlike AWG, the metric system is perfectly linear: a 10 mm² wire contains exactly twice as much conductive material as a 5 mm² wire.
AWG to mm² Conversion Chart
For quick reference, here are the most common conversions used in residential and commercial electrical wiring:
| AWG Size | Metric Area (mm²) | Diameter (mm) | Typical Ampacity |
|---|---|---|---|
| 14 AWG | 2.08 mm² | 1.63 mm | 15 A |
| 12 AWG | 3.31 mm² | 2.05 mm | 20 A |
| 10 AWG | 5.26 mm² | 2.59 mm | 30 A |
| 8 AWG | 8.37 mm² | 3.26 mm | 40 A |
| 6 AWG | 13.30 mm² | 4.11 mm | 55 A |
| 4 AWG | 21.15 mm² | 5.19 mm | 70 A |
How to Convert AWG to mm² (The Formula)
Because the AWG system is logarithmic, the mathematical formula to find the exact diameter and area of an AWG wire is highly specific:
Area (mm²) = (π / 4) × Diameter²
Note: For AWG sizes containing zeros (like 2/0 or 4/0), the AWG number is treated as negative. For example, 2/0 is treated as -1 in the mathematical formula.
Copper Wire Resistance by AWG
As a wire gets thicker (lower AWG number or higher mm²), its electrical resistance drops, allowing it to carry more current safely over long distances. Copper is highly conductive, but standard resistance still applies. For example, 10 AWG copper wire has a baseline resistance of about 3.28 Ω per kilometer (1.0 Ω per 1000 ft), while a thinner 14 AWG wire has a resistance of roughly 8.28 Ω per kilometer.