Measurement units in Library Manager


Hello people. I’m a new user of Kicad EDA. Newby. My previous EDA were are ACCEL and P-CAD. I’m not a electronic developer, it’s a my hobby. I draw various circuits of self-made devices. Since last years ago I begun to migrate to unproprietar software (MS Office --> LibreOffice firstly in 2014, MS Visio --> LibreCad later, MS Windows – > Ubuntu 16/17 in 2016). Queye to migrating is came to EDA now. I want to abandon PCAD and ACCEL. But:

  1. I have a various curcuits and pcbs designed in PCAD/ACCEL
  2. I have a my own libraries of components
  3. I have standards to design all in millimeter measuring units on scematic diagrams.

My question relates to creating of my own libraries of schematic components.

Library of components must include several similar components. For example, resistors. Every component must have a vector image, points of contacts, and some text attributes. Vector image drawn in ISU units. My resistor image is a rectangle of 2x5 millimeters size. I do not use inches and mils in schematic diagrams, only millimeters in use, only. I attemp to create a new library. “Resistors”. Run a Library Editor. And I can’t to change measurement units from mils to millimeters. I can’t set grid to millimeter’s scale. Consequently I can’t draw a rectangle in millimeters. How can I do it?


It’s not possible in KiCad today, maybe in future, if someone decides to write the code.


Kikad is a semi-death project? Nobody develop this?


People who engage in silly hyperbole will not be treated seriously. Unless you happen to be POTUS I guess.

Like I said, no.

I suppose we could have an FAQ entry “KiCad doesn’t have my favorite feature and now I’m mad”, but people who need it aren’t usually amenable to practical advice.


On the contrary, but there’s so much to do and the schematics isn’t so critical in many respects. Maybe within one or two years it may be changed dramatically.

Out of curiosity, you told “it’s a my hobby”, and even commercial companies don’t usually care about the units in shcematic drawings, so why should you care? Symbols are only symbols, there’s no need for them to be exact. They just need to work and communicate well their intented purpose. Footprints are a different thing, of course, and there you can use mm or in.


Kicad is a very live project.

While the pcb layout supports milimeters and inches, the schematic editor grid is set in inches. It is possible to switch the measurements to mm, but the grid will still be 1.27 , 2.54 , 5.08 mm.

In my case, I don’t mind what units are used for the schematic. In your case, try to use the official libraries as a start point to convert your schematics.


I felt sure this had to be on the big bug :wink: tracker somewhere: has what must be considered the “official word” from Wayne.


Yea Bobc, this is same thing that I describe above. Feature is craved since 2007 year… 10 years!!! Many people does not needed all libraries attached to kicad, many people can make their own personal libraries in metric units. Draw circuilts in inches - “stone age” (as described in bug). Very bad of course…

p.s. Can I write to launchpad too?

p.p.s. I wrote on Launchpad about this in bug 593555, as mentioned of bobc. But! There’s a very strange number of bug. This bug does not located on Kicad’ eeschema, as if he had not presented. I can’t find this with search. This bug is closed again?


No, that bug report, although it mentions ESchema, was primarily concerned with PCBNew, and that was addressed in 2010. Recently someone asked again about this, in 2017, with regards to ESchema and was given an answer. One person asking about something does make it “craved” by the majority of users, nor has been “craved” for 10 years.

In my opinion there is already enough trouble caused by users being able to change the grid size and then wonder why wires don’t connect to pins. Perhaps it would be less of an issue if ESchema implemented “snap to pin” but currently I think it would be better to simply have a fixed grid size that matches the standard library.


I mostly agree but at some point we all need to be on one measurement system. Being on the ‘wrong side’ of 65 I will continue to prefer to use imperial and let some younger generation bite that bullet though. :wink:


I think Eldar’s suggestion (make 1mm = 50 mil) is genius. It keeps compatibility with existing symbols, no one will ever take a ruler to the schematic and take measurements off it. It’s probably only a few lines of code to change.

However, considering the other 365 wishlist items, this would rank somewhere around 365th.


I have been known to do just that. If I want a figure for documentation to fit in a 6x6 box then it better not be 5.9x5.9.

John Eaton


Units are important in the layout, where we need exact dimensions.

In the schematic I want “user friendly” units as Wayne call them. It doesn’t matter if they are inches, mm or “generic” units.

Furthermore, in my opinion 50 and 25 (or 2 and 1 grid generic units) should be enough. Usually I plot to pdf and then I print with the shrink to printable area option.


Oh ok then, forget that idea. We will have to stick with inches.


The bug is slightly heated on Launchpad. Wayne is joined to discussion there.


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