Calculate net resistance

is there a way to calculate the resistance of a net between to pads?
I haven’t found one and also no entries in the forum or via google.

I’am a long time KiCad user but haven’t looked into KiCad scripting at all… I already used a lot of python outside KiCad.
I guess the length and width of each track belonging to one net is available via the scripting interface and I could do it by myself?

Many thanks for all hints or advises

To be clear. You want to do this internal to Kicad and not something like:

Yes, I want to do a long net with different widths along the path and i’am interested in quick way to show the resistance after modifying the net. I don’t want to enter all widths and lengths in Excel.

The resistance does not need to be exact but should be a good rough estimation.

I guess I found something to start with:

That’s my Plugin you’re looking at :smiley:

For another poster, I added Inductance to the calc’s. I may as well add Resistance…

It’s too simple to go through the Rig-a-ma-role so, below are the Calc’s you’d add for both Inductance and Resistance…

The sequence is a little inefficient but I didn’t want to re-structure it so, I did in a ‘thrown-together’ manner… But, it works.

NOTE: I hard-coded a Temperature of 30 deg C. You can do what you want about that, including a wx input prompt (to get user input)…

Screenshot of Code

Screenshot of Result (example)

I do plugins also, but mine plug into wall power outlets.

I think that some fairly expensive tools may use finite element analysis? On a consulting gig I had recently, the main design engineer had some DC drop analysis which worked with Altium. If I were to dig through some e-mails I may be able to find the name of the software.

For integration of FEM with KiCad see Finite Element Simulation (FEM) integrated into pcbnew (#8398) · Issues · KiCad / KiCad Source Code / kicad · GitLab

See my post

Many thanks for all the inputs.
Especially to BlackCoffee for his YouTube Video and for his script, very helpful! Thanks!


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