Actual size (Ctrl+1) is not working properly in Illustrator on Windows system

My gosh, thank you for saving my life!

Hi Tamzid,

Thanks for reaching out. I am hopeful that your query is answered by the suggestions shared above. If not, Could you please confirm if you are working with multiple monitors? If yes, then please check how does it look on the primary screen.

Regards,

Srishti

Peter gave some good background info, but either the first (by Katie) or the second answer (by Conrad) will solve your problem.

Either use Pixel Preview or uncheck the Display Print Size preference setting.

Fortunately, your Print documents show a good size !

That's a relief (especially on Windows...) It means that the co-operation between Illustrator, the operating system, and the screen resolution are behaving fairly well. So it's likely just a matter of your understanding of how a web-inclined measure works.

In contrast to many real-world sizes, our digital on-screen world still has a long road to travel when it comes to embracing a unit for measure. It may sound crazy, but after a few decades of being able to have "what you see if what you get" screen representations of your designs in print, it's still impossible to know at what size a design will be shown on a end-user's screen !

This is due to two phenomenas:

1. screens often present their size in pixels, but the physical size of a screen and its pixels varies per model;
2. there's no useful/sufficient standard (yet) for stating how many units there are in e.g. one inch of a display.

Well, actually the latter is not entirely exact – there are already three competing standards...

The most ancient one dates from the very first Apple Mac computer and the first incarnation of Adobe PostScript, both in 1984. The Mac's screen had a resolution of 72 pixels per inch, and the PostScript language was based on the similar idea of having 72 points (as the ancient typographic measure dictates) in an inch. So to reliably set the size of elements on a screen (like text and drawings), Apple and Adobe both initiated the first and golden standard of 72 dpi.

But screens rapidly became much sharper, with resolutions getting higher and higher by the year. By 2007, the first iPhone started at 163 ppi, but the current iPhone X is already at 463 ppi ! Of course, this is beneficial for having crisp text and drawings. Although most photos already look great on a screen at 200 dpi. BTW: only a toddler's eye has the acute capability to discern anything above 400 dpi at 1 foot distance...

Notes by Dr. Optoglass: The Resolution of the Human Eye

However, feeling competitive, companies like Microsoft and Google have both defined their own and newer standards for stating screen measures based on pixels, being 124 ppi/dpi and 160 ppi/dpi, respectively. Don't think of this mess as something new. In the Middle Ages there were also many different units of measure for almost everything and every country...

Back to Adobe Illustrator: because of its PostScript roots, Illustrator adheres to the old and actually quite coarse standard of 72 dpi, so 1 inch is 72 pixels. Which is exactly what happens when you draw a square of 72 pixels by 72 pixels, it's 1 inch (6 x 6 picas on my antique type ruler...)

About the difference between dpi and ppi (dots per inch vs pixels per inch), that's just a dogmatic debate. Yes, dpi belongs to the printing world (ink dots) and ppi was intended for screen (pixels). But people use them interchangeably, and that's no big deal...

And for those who are serious about being precise: we're talking about the American inch, which is actually an old version of the English inch, which altered a few times after being adopted in America. That's why you can set your preferred version in software like InDesign.

I'm not sure of the reason, but I might have a cause and another workaround. Illustrator recently redid how zoom works, to provide improved Actual Size preview for print documents. I think they try to get the screen resolution from the OS. But like you saw, it doesn't work right for documents using pixel units.

A workaround is to disable the new function. Go into Preferences > General and disable Display Print Size at 100% Zoom. That worked for me.

Now the only problem is that we have to change that setting depending on which unit of measure we're using.

Looks like the Pixel Preview workaround might be better (Katie posted as I was still writing)

It looks like this also is being discussed on the Illustrator Feedback site:

Actual Size view menu does not display at actual size... – Adobe Illustrator Feedback

Yes. It seems if you turn on View> Pixel Preview it will then show correctly.