Yiannis Michael's Trace Width Calculator Does One Job, and Does It Well

Maker Yiannis Michael has released a tool that aims to do one job and do it well: calculate exactly how wide your PCB traces have to be in order to support a given current.

"I always found confusing how an open-source tool for this type of electronics design use didn't exist, therefore I decided to make one," Michael explains. "Through the project I wanted to allow the study of how trace widths are calculated, since I found the complexities behind that interesting. Also I wanted to collect most of the available online trace width calculator implementations, and try to improve on them, while implementing them on an open-source offline command-line tool."

The command-line tool is simple in its use, yet surprisingly deep in its implementation: the user supplies the weight of copper and the maximum desired current, and the resulting width is returned. But that's only the most basic use of the tool: board designers can also provide the maximum desired temperature rise, the trace length, the thickness of the PCB substrate, its thermal conductivity, the plan cross-sectional area and distance, and resistivity, add notes, and choose between metric and imperial outputs.

The calculations, meanwhile, can pass through no fewer than four different methods: one based on IPC International's IPC-2221 standard, and three separate methods for the IPC-2152 standard — each of which provides a different result. "The completely different implementations of the IPC-2152 standard does put in question the validity of these calculators and their implementations," Michael admits. "Thankfully, due to the open-source nature of the project, the differences between the implementations are clearly viewable, and the user can freely choose the one that seems best."

The source code for the tool has been published on GitHub under the reciprocal GNU General Public License 3, along with a precompiled binary for Microsoft Windows.