Trace Layer
Specifications
Required Width (mm)
0.781 mm
Suitable trace width in metric units
Required Width (mils)
30.8 mils
1 mil = 0.001 inches (imperial sizing)
Calculated Copper Thickness
1.378 mils
Equivalent to 0.035 mm
Cross Section Area
42.4 mils²
Total needed conductor copper area
IPC-2221 Designing Reference
The calculator uses the mathematical equations defined by the **IPC-2221** (formerly MIL-STD-275) specification guidelines. These guidelines establish safe trace width margins to prevent excessive temperature rise from resistive heating, which could degrade PCB FR-4 laminate substrates or lift copper tracks.
External vs. Internal Layers: Inner layers (sandwiched inside multilayer boards) dissipate heat significantly slower than outer layers exposed directly to ambient air or solder masks. Therefore, internal traces require approximately **double the width** of external traces to carry the same current safely.