Well, I had most of this typed out when I saw you already replied. But I'll post anyway, because there's some important info.
I can totally understand what you mean!
First I should tell you that Inkscape developers will probably not see your comments here. For some reason, they don't like to participate in bb style forums. For some reason, they like mailing lists (
https://inkscape.org/en/community/mailing-lists/). Sometimes you can catch them on IRC (
https://inkscape.org/en/community/discussion/).
If you want to make a formal request for this (which I think is a good idea) here is info for that. I know this is a feature request, but the Inkscape project uses the bug tracker for that.
https://inkscape.org/en/contribute/report-bugs/More towards answering your specific question -- I'm not sure if I know the proper formula. I don't mind doing the math, but need the formula to do it.
But before that, I need to tell you something, that is probably going to complicate things for you. In the new stable version 0.92, the native dpi has been changed to 96 DPI. So version 0.91 and earlier, it's 90 dpi. But from 0.92 on, it's 96. The reason for that is to be more compliant with SVG standards, which call for 96 dpi.
Next, you report your monitor resolution as 90.05, which is confusing to me. I usually see resolution as n x n (number x number). For example, my monitor is 1366 x 768.
Oh I see. You mean on the site you referenced, your DPI was calculated to be 90.05? (mine is calculated to be 104.47).
Well, the first thing that comes to mind, is for Inkscape version 0.91 and earlier, you monitor's DPI is almost exactly the same as Inkscape's. So no change needed, right? (0.05 dots would hardly be noticable, would it?)
For Inkscape version 0.92 and later, as far as I remember from school (40 to 50 years ago) you would just take 90.5 and divide by 96.....or maybe it's the other way around 96 divided by 90.5. And that's the conversion factor. So whichever way is correct, you set Inkscape to zoom by that amount.
The answer to the former is 0.9380208333333333, while the answer to the latter is 1.066074403109384.
So no matter which one is the correct answer, Inkscape can only zoom by whole numbers.
Here's where I saw you posted.
So I got a slightly different number than you. Note that I didn't move the decimal point yet, but mine is probably more accurate. Although as you said, since inkscape can only zoom in whole numbers, it comes out the same.
I guess I'm curious what kind of project you're working on where 6% zoom makes that much difference. Just pure curiosity, don't feel obligated to answer.
