placing an image that's the same size as the document page size but somehow got half of the ppi

Forum|Forum|18 hours ago
July 2, 2026
2 replies
24 views

i created an image in 1600x2400px @150ppi and relink to a 1600x2400 web document with 50px margin, but somehow the effective ppi went down to 75 ppi. Actual ppi still remain 150. This is driving me crazy, Please help.

rob day

Community Expert

This is driving me crazy,

Hi @MonaB , Also an InDesign page has no resolution—it’s a vector object not an image.

There is a Pixel Ruler Unit, which has no relationship to page’s output or export resolution. That’s more obvious if you change your Ruler Units from Pixels to Inches:

leo.r

Community Expert

InDesign pixel unit measurements are basically only valid when you place 72 ppi images and do not scale them. It’s totally different from Photoshop pixels. If you switch to physical units (inch, mm, etc.) you’ll get consistently expected results.

E

Eugene Tyson

Community Expert

@leo.r is correct - just to elaborate a bit

The confusing part is that InDesign pixels are not the same thing as Photoshop image pixels.

Your image is 1600 × 2400 px at 150 ppi, so its physical size is about 10.67 × 16 inches.

But an InDesign document set to 1600 × 2400 px is effectively much larger physically, because InDesign’s pixel unit is based around 72 units per inch. So a 1600 px wide InDesign page is about 22.22 inches wide.

That means when you fit your 150 ppi image to that page/frame, InDesign is scaling it to around 200%. Once a 150 ppi image is used at 200%, the effective resolution becomes about 75 ppi.

So nothing is wrong with the image. The Actual PPI stays at 150 because that is the image’s own metadata. The Effective PPI drops to 75 because the image is being enlarged in the layout.

As Leo says - for predictable results, either work in physical units, or make the image 72 ppi if you want its pixel dimensions to match an InDesign pixel-based document without scaling.

leo.r

Community Expert

Exactly.

And as an additional demonstration for @MonaB, image pixel dimensions remain the same no matter how you scale it and how its dimensions correspond to InDesign pixel rulers:

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