Component sizes in schematic editor and imported schematic

Are you using R or R_Small?

Here’s another way to approach the problem: reduce the size of your sheet under Page Settings. Say use A5 instead of A4. Then you’ll find that your schematic fills up more of the page.

I hope this explanation in the FAQs will ease the complication of creating personal libraries. You will eventually need them.
There is a lot of “good stuff” in the FAQs.

KiCad does have a zoom button in the schematic editor (also works with the mouse scrollwheel) and you can use it to make resistors bigger. In the screenshot below, this resistor measures 30cm from pin attachment point to pin attachment point, and at maximum zoom it measures 67cm.

This is the “normal” R from the “Device” library, and not the R_small. It’s quite common to place the values inside the “European” version of the resistor. I do not see any advantage of using “R_small”, because then you have to put the value outside of the resistor, and it takes up the same amount of space.

About a year ago I bought myself a 4k monitor with a 107cm diagonal, and it is very comfortable to work with. I have always tried to get big monitors. I already bought a 17" CRT when most people were still working with a 14" CRT and those things were expensive back then, combined with being young and not having much money. Later, I also worked for years with two 24" TFT LCD’s, and this works great with KiCad. You can put the schematic on one monitor, and the PCB on another, or use the other for reading .pdf or internet info, spreadsheets or other notes, etc. At the moment I still have a two monitor setup. I still have one one of the 24" LCD’s in portrait mode next to the big one (they have almost the same height) but that monitor is almost always off. I’ve got plenty of screen area on the big monitor and just have no need for turning it on. I also guess the old smaller monitor uses a lot more electricity then the new big one.

using just plane R. I will try page settings. Thanks.

I just used plane R not R small. The resistor is tiny on my screen. Will try first reducing page size as suggested.

So why did you ask the same question in:

Please do remember we are also volunteers and do not want to waste time and effort on answerering the same question from the same person twice. It also makes it more difficult for others reading this forum to find answers to their own questions.

Retiredfeline suggested to reduce the paper size, which would make schematic symbols bigger when the schematic is first opened. Did you manage to do that?

yes tried that and it does not work. wouldn’t be asking again if I got the right answer. after considerable amount of searching found a hot key for value of a resistor V. But no mention of ohms.
Have a reference to right click on component to change component scale. There is no ‘change component scale’ (size) on my version for windows 10. Tried looking under hot keys found the V but seems to be no hot key for size(scale) of a component.

I am actually confused about what the question is.
KiCad’s resistors are quite well proportioned compared to other schematic symbols when you draw a schematic, and with the zoom function you can make it any size that fits on your monitor.

Repeating the same question is also not going to help you. Formulating better questions is much more likely to improve results. Maybe this helps:

The question is how do I save the increased size of the resistor that I have created with the zoom function? When I come back later to the schematic the resistor is again reduced to a tiny size. Can’t see the confusion here. If the read only resistor size which is given in kicad was a decent size I wouldn’t be having this problem. You may be lucky and are getting decent size resistors on your monitor. I need a magnifying glass to see mine.

I think that the OP’s question gets to one pet peeve of mine. Especially in the days of hand drawn or mechanically drawn schematic diagrams, the draw-er would put long “wires” between the components which are spread out on a large piece of paper which might cover a desk. Of course, the large paper can be useful if the schematic contains a large number of components. But I have always thought it was better to crowd the components more closely together. “How closely?” is a subjective question but the association between the symbols and the text should be clear and unambiguous. The schematic should be easy to read.

The whole point is to be able to see as much of the schematic as possible clearly on a screen (or piece of paper) in a view that is also fully readable.

Basically then I am reinforcing the opinion of using a smaller sheet of paper and crowding the components more closely so as to make everything more readable.

I submit the following as an example. I suppose you may need to zoom in order to read SOME of the text but I like to think that that smaller text is less essential. Does this shed light on the subject or throw it into a tailspin?
Slug_O_Cuter_04_12-11-2021c.pdf (117.2 KB)
BTW I do not see any issue with the size of the resistor symbol. I think mine is derived from the smaller American style in the standard schematic library.

I think the only way to have larger symbols permanently is to make them and store them in personal libraries.

1 Like

Short answer:

The confusion started with that resistors do not have a “fixed size”, and their “size” does not mean much to me. It’s all vectors and zoomable. I’ve become so used to zooming in on a schematic directly after opening that I am (were) not even concious of it, and it never registered as a “problem” for me. Changing the size of the resistor in the library as suggested earlier also does not seem a valid method. As I see it, it is not about “resistor size”, but about “Default zoom level” when a schematic is opened.

Long answer:

KiCad seems to zoom to the full page at the moment of opening the schematic editor. So the “on screen” size of a resistor depends on:

  1. The size of your monitor,
  2. The size of the schematic editor window.
  3. The selected paper size in the schematic.

1). Size of the monitor is not “static”. About a year ago I bought a 4k monitor, but not such a thing with small pixels, but with a normal pixel pitch and a 107cm diagonal. But even so, with the schematic editor maximized a resistor is still only 17mm for an A4 sheet. (KiCad unfortunately wastes quite a lot of white space around the schematic border). And the first action I do after opening a schematic is zooming in. It’s become so habitual that I stopped noticing it long ago.

2). KiCad normally saves the size and location of the schematic editor when you close it, and will re-open at the same size.

3). What is your selected paper size? (From Schematic Editor / File / Page Settings) For me it defaults to an A4 in landscape format. KiCad’s paper size is unfortunately also quite wasteful. It wastes a about a cm of paper space for the border, and the titleblock is also relatively big, especially with the space reserved for the “4 comment lines” which nobody seems to use. You can define custom sheets with the Drawing Sheet Editor but it’s a bit of a bore to do so.

Other Ideas and workarounds:

If you press [Ctrl + Home], then the schematic editor zooms to the “area in use”. If your “schematic” only consists of a single resistor, then that resistor will be full screen.

When the PCB Editor is opened, it defaults to zoom tho the PCB outline, and not to the paper size as the schematic editor does. This is inconsistent.

In KiCad V7, the PCB Editor has definable viewports, and this is a relatively new feature. It would be nice if a “default Viewport” could be defined, which is then used at the moment the PCB editor is started, but as far as I know this is not (yet) implemented. It is possible that similar features are planned for some future version of the Schematic Editor to.

If your goal is to have a quick reference of multiple schematics and switching between them, then it may be a better option at the moment to export the schematic as a .PDF or .SVG

It solves the problem for the printed circuit.

On screen I cannot see any problem at all: the smaller the display, the bigger zoom in, regardless of the size of the resistor.

I see.
I use A4 sheet and want to have whole schematic at one sheet. For some schematics it is no problem, but for some more complicated it is. So I defined all symbols to be as small as possible (using standard 50 mils grid for wire drawing) to allow me draw schematic as dense as possible.
An example of my schematic:


  1. The size of resistor symbol in library. And it is what the question is about, I think.

I did it once when starting to use KiCad. As I start each project by copying the older one I have always my frame already at schematic. During 6 years passed I forgot if it was bore or not to do so.
To not waste a space my frame is smaller than KiCads origin:

That was part of my confusion, and I am relieved that I’m not the only one confused here.
As I understand it now, it is about the size of “a resistor” (or other parts) at the moment that the schematic is first opened and without zooming (so don’t touch the scroll wheel) At that moment the resistors do look quite small, and I think that is the problem in this thread. Size of resistors is very near to optimal compared to other library symbols.

It’s easy to confuse “size” of a part (which is relative to other parts) and “zoom level”. I interpret as that petercl14 wants to configure a “default viewport” which is used at the moment the Schematic Editor is started. This does seem a nice feature to have, but it’s just not implemented at the moment.

@petercl14 Am I right in believing it is about this “default zoom level / viewport” and not about the size of resistors relative to other schematic symbols?

I think it is about resistor size not related to anything, but about its size as defined in symbol editor (not how you see it, but how big (in mils) it is). If you add pin to symbol you can specify its length so it is not abstraction vector definition as you try to interpret it from this thread beginning but it has some defined size.
And about your question regarding relative to other symbols - when OP will see resistor as he wants then he will ask how to make capacitor symbol bigger :slight_smile:

I’d say there is enough speculation to confirm the confusion.

And I don’t like speculation much in this context, so I’ll leave it up to petercl14 to resovle that part.

obviously if I know how to make a resistor bigger that same method would be used to make any symbol including capacitors bigger.
Found these instructions to change size;

  1. select component you want to resize.
  2. right click to get ‘change component scale’.
  3. zoom in or out to get desired size.
    Unfortunately for me when I right click there is no ‘change component scale’.

got it in one. it is about the size of the resistor the moment the schematic is first opened. I now have the resistor ohm size added to the resistor . I added this with hot key ‘L’. Every time schematic is opened now shows resistor with ohm size but you need a magnifying glass to see it.
All I need now is a hot key for the resistor size so that every time I open the schematic the resistor will be shown at a decent size. Please don’t now get confused over resistor size and its ohm size. Can’t find in the list of hot keys one for resistor size Should be according to another source a ‘change component scale’ but I don’t have that on my version 7 of kicad.

Hi @petercl14 ,
Right click on symbol opens “Select on PCB” menu which does not list “change component scale”.

also, Hotkey “L” opens “Label Properties” box. This is not the the Ref. or Value of the symbol.

I’m pretty sure that has never existed in Kicad, at least not in 4, 5, 6 or 7.

One other thing to avoid confusion on this forum. The Schematic has Symbols and the PCB has Footprints. Components are the pieces of stuff you have on your workbench.

Finally, is it only the size of the resistor symbol you consider too small, or are any other symbols too small also?