How to Change a PDF's Page Size (A4, Letter, Legal)
2026-07-15
Page size is invisible until it isn't. A document created on US Letter and printed on A4 comes out with an unexpected strip of margin and a scaling prompt. A report assembled from several sources prints with pages that do not line up in the tray. Standardising the size fixes both.
Step by step
- Open the Resize PDF Pages tool.
- Drop in your PDF.
- Pick the target size: A4, US Letter, Legal, A3 or A5.
- Download the resized file.
A4 versus US Letter
A4 measures 210 × 297 mm and is standard almost everywhere outside North America. US Letter is 216 × 279 mm — slightly wider and noticeably shorter. They are close enough that the difference is easy to miss on screen and impossible to miss when printed: one produces uneven side margins, the other a gap at the bottom, and either way your reader gets a "scale to fit?" dialog.
Nothing gets cropped
Each page is scaled to fit inside the new dimensions and centred, so every element that was on the page is still on the page. Because PDF content is largely vector, the scaling is lossless — text stays sharp at any size, and only embedded photographs are resampled, exactly as any viewer would do when displaying them.
Keeping orientation
Leave "keep each page's orientation" switched on unless you have a reason not to. Without it, a landscape page forced onto a portrait sheet is shrunk to fit the narrower dimension and ends up tiny. With it, the target size is turned to match and the page fills the sheet.
The other sizes
A3 is useful for posters, plans and anything with a large table. A5 makes booklets and handouts. Legal exists because some contracts still insist on it.