AWG to mm² Calculator
Convert American Wire Gauge (AWG) to cross-sectional area in mm², or reverse from mm² to the nearest AWG size.
What is AWG and why convert to mm²?
AWG (American Wire Gauge) is a sizing system commonly used in the United States and Canada. Many datasheets, electrical standards, and product listings outside North America use metric conductor area in square millimeters (mm²). That means engineers, electricians, and DIY users often need a quick AWG to mm² conversion.
This page gives you both: a practical calculator and a reference guide so you can select the right wire size with confidence.
How the AWG to mm² conversion works
Step 1: Convert AWG to diameter
Wire diameter in millimeters is calculated from AWG using:
d(mm) = 0.127 × 92((36 - AWG) / 39)
Step 2: Convert diameter to cross-sectional area
Then area is:
A(mm²) = (π/4) × d(mm)2
The reverse conversion (mm² to AWG) uses logarithms and then rounds to the nearest standard AWG size for practical use.
Common AWG to mm² conversion chart
| AWG | Approx. mm² | Typical use |
|---|---|---|
| 24 | 0.205 | Signal wiring, low current electronics |
| 22 | 0.326 | Control wiring, sensors |
| 20 | 0.518 | Small harnesses, low-power circuits |
| 18 | 0.823 | Automotive accessories, control panels |
| 16 | 1.31 | Lighting and medium current runs |
| 14 | 2.08 | Branch circuits (region/code dependent) |
| 12 | 3.31 | Higher load branch circuits |
| 10 | 5.26 | Heavier circuits, short feeder runs |
| 8 | 8.37 | Feeders and high-current devices |
| 6 | 13.3 | Subpanels, large appliances |
| 4 | 21.1 | High-current distribution |
| 2 | 33.6 | Service and heavy feeders |
| 1/0 | 53.5 | Main service conductors |
| 2/0 | 67.4 | Large service and industrial use |
| 3/0 | 85.0 | Industrial/high-current feeders |
| 4/0 | 107.2 | Very high current applications |
How to choose the right wire size
- Current (amps): Primary driver of wire size selection.
- Length of run: Longer runs need larger wire to control voltage drop.
- Conductor material: Copper and aluminum have different resistivity.
- Temperature rating: Insulation type changes ampacity limits.
- Installation method: Bundled wires and conduit can reduce allowable current.
- Local code: Always verify with NEC, IEC, or your local electrical authority.
AWG vs mm²: important practical notes
AWG is logarithmic, not linear. A small AWG number change can mean a significant difference in area and resistance. Also, cables sold as “equivalent” may vary slightly due to strand count, manufacturing tolerance, and insulation thickness.
For critical applications (high current, long runs, safety systems), use this conversion as a starting point, then confirm voltage drop, temperature rise, and code compliance.
FAQ
Is 2.5 mm² the same as 14 AWG?
They are close, but not identical. 14 AWG is about 2.08 mm², while 2.5 mm² is closer to around 13 AWG equivalent (non-standard in AWG labeling).
Can I directly swap AWG and mm² cable sizes?
Not always. Always check allowable ampacity, insulation temperature class, and code requirements.
Does stranded wire change this conversion?
The geometric conductor area can be equivalent, but strand construction and packing may slightly affect measured diameter and flexibility. The electrical area target is what matters most.
Bottom line
This AWG to mm² calculator gives fast, accurate conversions for planning and comparison. Use it to translate specs, validate wire selections, and reduce mistakes when working across US and metric standards.