Exported PDF from InDesign it is dimensionally larger than the InDesign file. Why?

[S de Saulles]

When I export a PDF from InDesign 2025, I get a file that is dimensionally larger than the InDesign file.

It should be identical in size.

How can I control the PDF export to be the correct / identical dimensions?

When I export as a JPEG and open it in Photoshop, I get a file that is exactly the 297mm wide that it should be (A4 landscape) .

Exporting as a PDF and I get a PDF that is about 384mm wide, so a linear scaling of almost exactly 130%. It is driving me nuts! I've tried exporting as CS4, opening in InDesign 2024, exactly the same.

I have searched here and on the web, and found lots of suggestions about turning crop marks and bleed, etc on and off, but it's not that. (and lots of AI-generated nonsense that is talking about controlling file size of a PDF output, not dimensional size)

Do you have any thoughts on what might be causing this madness, and even better, how to correct it?

Many Thanks

Stephen

[Robert at ID-Tasker]

Do you export for PRINT or INTERACTIVE?

If for PRINT - it should be larger to accomodate, at lest, so called "bleed" area - part of the paper that will be cut off but is required.

What do you have set - checked - in the MARKS AND BLEEDS of the PDF Export?

[S de Saulles]

Thanks for the suggestion Robert, but no, as in the post I've read (and tried) with and without bleed and printer's marks to no avail.

I think I have now discovered it is a problem with the dog of a program that is Acrobat Pro rather than with InDesign, I should have checked but assumed it was an Export setting in InDesign.

Anyhow, I've just done a little 100mm square test file in InDesign and exported with no bleeds or printer's marks.

Open the exact same exported PDF file in Adobe Illustrator, it measures 100mm square as it should, open it in Acrobat Pro and it measures 129mm square, see attached.

Acrobat always seems to be a bit of a weird "outlier" with quite different interface, etc., to the rest of the Adobe suite of programs, and it seems to have its own interpretation of a millimetre, too! Perhaps I'm missing something blooming obvious, but I have my units set to mm in Acrobat. I think that's the only place to set the "scale." Anyway, this should perhaps now move to the Acrobat problem pages.

At least I am reassured the output from InDesign can be trusted re physical size!

[Willi Adelberger]

How do you measure the size in Acrobat?

[Robert at ID-Tasker]

How do you measure the size in Acrobat?

By @Willi Adelberger

There is ruler displayed? 

[Robert at ID-Tasker]

@S de Saulles

WOW!

Will check this later, when I get to my laptop.

[Brad @ Roaring Mouse · Accepted solution]

This is probably due to an inproperly-set Page Display > Resolution setting in your Acrobat Preferences. This is particularly a problem with hi-pitch monitors such as Retina displays.

By default, it gets a setting returned from your MAIN monitor driver (System Setting). If you've scaled your monitor up in your driver for any reason, or are viewing the file on a secondary monitor, this will cause issues.

[Robert at ID-Tasker]

Brad @ Roaring Mouse

But ruler clearly shows 129? 

[S de Saulles]

Hi Brad, 

Wow, you're absolutely correct!!. If I change my display resolution, the size of the rulers will also change. It's absolute madness! 

I'm just testing on my retina-display MacBook Pro M1 Max, 1496 x 967 pixels—which I would never ever use as it's like using something from a decade ago—and it gives a correct 100mm square.

If I go to the display "Native" resolution of 3456 x 2234 I get that 100mm square showing as well over 200mm wide.

So, in what world is that useful, I wonder? Once again, Adobe Acrobat seems like a mongrel dog hotch-potch of a program. Why, oh, why would Adobe make it do that? (I have read the later post that gives a reason, but really??? Have that as an override, perhaps, but not as the default.)

Anyhow, rant over, and many thanks for pointing me to that weird anomaly - I will never trust rulers in Acrobat - lesson learned!

Thank you for your knowledge. I don't think I would ever have discovered that as the cause in two lifetimes.

Stephen

[Eugene Tyson · Accepted solution]

This is what I see

In Acrobat if I go to preferences and go to Page Display

Now the dimensions are not correct in the ruler viewing 

But if you look in the bottom left corner if you hover (there's a preference to have this on all the time)

It shows the correct dimensions

Set to custom resolution

And it's back to correct viewing 

It also appears to be how your System Scaling is set - so I changed my Custom Resolution to 110 to counter balance the system scaling

If your system uses a scaling factor (e.g., 125% or 150% on high-resolution displays), Acrobat may miscalculate the pixel density, leading to incorrect ruler measurements.

Why Not 120 PPI?
Even though 96 × 1.25 = 120, some factors might alter it:

Physical Monitor DPI: Some monitors have a native PPI that's not exactly 96.
Acrobat’s Internal Handling of Scaling: It may round values or apply different scaling logic.
OS Behavior: Windows sometimes applies fractional scaling adjustments that slightly shift the result.

It’s a mix of OS scaling quirks, Acrobat’s handling of DPI, and your specific display’s PPI.

Correcting to specific resolution in Acrobat will resolve your issue. 

Even though the Ruler is a mixed bag of settings - it shows the actual correct dimensions of the document in the bottom left corner. 

Acrobat ruler is showing you the size it is at the resolution set in the Preferences - so to speak.

It doesn't just show a "fixed" measurement like a physical ruler would.
Instead, the ruler shows the calculation of the document based on the display resolution (PPI) set in Preferences and adjusts accordingly.