Advanced Wire Size Converter
Example Data Table
This table shows common metric wire areas and their closest AWG matches.
| Area mm² | Closest AWG | AWG Area mm² | Diameter mm | Typical Use Note |
|---|---|---|---|---|
| 0.50 | 20 AWG | 0.518 | 0.812 | Small control wires |
| 0.75 | 18 AWG | 0.823 | 1.024 | Light signal circuits |
| 1.50 | 15 AWG | 1.650 | 1.450 | Light power runs |
| 2.50 | 13 AWG | 2.624 | 1.828 | General branch wiring |
| 4.00 | 11 AWG | 4.172 | 2.305 | Higher load circuits |
| 6.00 | 9 AWG | 6.634 | 2.906 | Feeder or equipment wiring |
| 10.00 | 7 AWG | 10.549 | 3.665 | Larger feeders |
| 16.00 | 5 AWG | 16.773 | 4.621 | Heavy load conductors |
| 25.00 | 3 AWG | 26.670 | 5.827 | Subpanel planning |
| 35.00 | 2 AWG | 33.631 | 6.544 | Large power conductors |
Formula Used
The calculator converts metric conductor area into an equivalent American Wire Gauge value. It first finds the theoretical gauge from the area in square millimeters.
Exact AWG formula:
AWG = 36 - 19.5 × log(A / 0.012668) / log(92)
Here, A is the conductor area in mm².
The value 0.012668 is the approximate area of 36 AWG in mm².
AWG area formula:
A = 0.012668 × 92^((36 - n) / 19.5)
The calculator also estimates circular mils, conductor diameter, resistance, and voltage drop. Resistance uses material resistivity and a temperature correction.
How to Use This Calculator
- Enter one or more wire areas in square millimeters.
- Select nearest, larger, or smaller AWG matching.
- Choose copper or aluminum for resistance estimates.
- Enter length, current, voltage, and temperature if needed.
- Press the calculate button to view results above the form.
- Use the CSV or PDF button to save the result table.
For real installations, compare the result with insulation rating, bundling, conduit fill, voltage drop limits, and applicable code tables.
Guide to MM2 and AWG Wire Conversion
Why Metric Area Matters
Wire area is often listed in square millimeters outside North America. AWG is common in North American catalogs and drawings. A direct conversion helps when parts, terminals, and cables use different standards. This calculator gives a clear bridge between both systems. It also shows the nearby standard gauge choices.
Nearest Gauge Is Not Always Best
The nearest AWG is useful for comparison. Yet a project may need the next larger conductor. Larger conductors reduce resistance and voltage drop. They can also provide better thermal margin. Smaller conductors should not be selected for power wiring without checking code requirements. Use the rounding mode to match your design intent.
Diameter and Circular Mils
Area alone does not tell the full story. The tool also estimates conductor diameter. Diameter helps when checking terminals, ferrules, glands, and crimp sleeves. Circular mils are included because many wire references still use that unit. These extra values make the result easier to compare with older charts.
Resistance and Voltage Drop
Long wire runs lose voltage. The amount depends on area, material, length, current, and temperature. Copper has lower resistance than aluminum for the same size. Higher temperature raises resistance. This page includes a practical voltage drop estimate. Treat it as a planning value, not a final safety approval.
Good Design Practice
Wire sizing should consider more than conversion. Current rating, insulation type, ambient heat, installation method, and local rules matter. Devices may also require a minimum terminal size. Use this calculator for fast comparison and documentation. Then confirm the final cable with approved electrical references.
FAQs
1. What does mm2 mean in wire sizing?
It means square millimeters. It describes the cross-sectional area of the conductor. Larger area usually means lower resistance and greater current capacity.
2. What does AWG mean?
AWG means American Wire Gauge. It is a gauge system where smaller numbers usually represent larger conductors. Large sizes may use 1/0, 2/0, 3/0, or 4/0 labels.
3. Is the nearest AWG always safe?
No. The nearest gauge is only a mathematical match. Electrical safety also depends on current, insulation, temperature, conduit, bundling, and local code rules.
4. Why does the calculator show larger and smaller AWG?
It helps compare choices around the exact value. The next larger conductor has more area. The next smaller conductor has less area and may not be suitable.
5. Can I enter many mm2 values together?
Yes. Enter values on separate lines or separate them with spaces, commas, or semicolons. The result table will show each conversion separately.
6. Why is voltage drop included?
Voltage drop helps estimate performance over long runs. It depends on current, length, material, and resistance. It is useful for early planning.
7. Does copper or aluminum affect AWG conversion?
The area-to-AWG conversion does not change by material. Resistance and voltage drop estimates do change because copper and aluminum have different resistivity.
8. Can I use this for final electrical design?
Use it for conversion and planning. Final wire selection should follow approved electrical codes, manufacturer data, and qualified engineering guidance.