Set EVERYTHING to metric?

Being new to the program, I had the schematic set to millimetres, but the rest of the preferences are still in imperial.

How do I make it to be in millimetres. Do I have to convert everything beforehand to mils and then put it in? I also found out that my schematic grid isn’t defaulted to metric lengths like 1 mm but are in every 0.05 inches (50 mils). How do I make everything metric and not have to worry about imperial units?

You have an inch/mm button on the left ribbon so the GUI uses either one of the systems. Once you select there metric, you set everything in mm’s. I assume these above are just for the initial setup, but frankly I’ve never poked there myself and it never stopped me using metric all-round :wink:

EEschema is being refurbished as we speak and that’s one of the things that will change… don’t hold your breadth though.

Yea everything maybe in millimeters when I select it, but they’re still the weird values that originated from the imperial system.

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Which isn’t surprising after all, I think. You are free to set the values yourself, if you prefer even metric numbers to the odd/weird values originating from the imperial-> metric conversion, go for it. But be aware that most of the schematic parts and footprint models are drawn/specified in imperial units (inch, mil), so don’t be surprised if only one pin/pad snaps to the grid when using even metric numbers for grid etc.

Or maybe, I can keep everything in inches and treat it like millimeters. The thing is everything else around me like my breadboard are in millimetres.

schematic =/= breadboard or real world

PCBnew is ahead in that regard and can do full metric since it’s refurbished version came out in 2014 (I think).
EEschema is lagging, but there is just so many people working on it.

Be aware that if you print your schematic it will need to be scaled if you treat it like that.

In reality, the grid size of 50 mil are just used as schematic units, that they come out as 50 mil in reality when printing is just a fact. If you change the grid size to a size that is not an integer multiple of 50 mil you will have a hard time to connect wires in your schematic to symbols.


I like what you said. So since everything is defaulted in inches, I’ll just treat it as some unknown unit and resize it to millimeters when I want to print it. I’ll be working in inches now, but ignoring that fact it’s called inches.

Could it be that you want to draw the schematic and use that as a template/overlay for your breadboard designs? In this case you can safely ignore the schematic grid units and just have to scale the print that it fits to your preferred “real world” grid.

Slightly off-topic and out of curiosity: What kind of breadboards do you use? The breadboards and Veroboards on my workbench all have 2,54 mm = 0,1 inch = 100 mil spacing.

2.54… oh… measuring it with a ruler it looked like 2.5…
America y u infest electronics with inferior imperial system?
ok I’ll work with inches, I just know that imperial has some very awkward conversions…

LOL, no it’s just legacy and pretty much on the way out.
Modern devices are mostly defined in mm now.
But we sure will have to appreciate the legacy for a couple more decades in certain niches :slight_smile:

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Year 2020 and I am still struggling with Imperial after 70 years, and I am English!
Those mils are not imperial, (that would be thou) they are American and confuse me even more. For years I thought they were mm!
Time to move on and change the whole thing to metric, it can always be printed x .254 or whatever at the end.
I am still trying to get it to use 1.0 mm, not 0.991 mm.

It is just the schematic (everything else KiCad has been metric since basically forever). Units make no sense there. Just think of the units there as the minimum grid separation and be done with it.

What Rene said - and additionally, you should NEVER EVER change the default grids in the symbol editor or schematic editor except for graphics. It’s especially important that symbol pins and schematic wires use the same grid, otherwise you will get into big problems.

Additionally: every user and every dev is aware that this is not a good thing but there were until now higher priority things to fix. Especially as it is quite easy to work with eeschema as long as one stays at 50 mil grid.

The hope really is that snap to pins will come and all this grid stuff is made obsolete.

It is the EEschema that irks me, why should a metric user use a 50 mil grid and 0.991 mm fonts?
I guess we will always agree to differ on this issue. I do not do a lot these days, but a lot of PCB items are now made to mm and this would be reflected in its footprint, as you point out that would make the grid out of kilter anyway.
Whatever, 2.54 mm pin spacing is being replaced by 2.0 mm spacing, a mix of the two will keep all amused for decades. Some of us just think we should not prolong this agony into the coming generations.

Go *&^%$#@! them americans. They essentially switched to metric when some obscure unit some call an inch was defined as 25.4mm. That was about 100 years ago. Back then some government official put “advisory” in some memo because he did not have the guts to write “mandatory”. and because of that we have space probes crashing on Mars, Hot air balloons ordered in the wrong size and PCB connectors that are made in a pitch of both 5mm and 5.08mm, and if they have more then 4 pins, M & F are not interchangeable.

Just a few years ago I bought a brand new Chinese Lathe, and after I installed it at home I discovered that the measurement of the tailstock does not make sense.

Units are important in the layout; in the schematic they aren’t.

In eeschema I think of “length units” no matter its name is mm, km, inches or miles.

(By the way, I guess mil comes from 1/1000 as well as thou comes from one thousandth. I agree the sentence Thou should use thous must pass away)

Yes, squashing 4 metric pins onto 4 Imperial pins works, as does re-forming 74xx pins, I understand Russia made a metric 74xx series. Here is the first problem, measuring to see if the pins are that .009 mm closer or further apart than you thought!