About the PDF Page Size Checker
Before you print or send a PDF, it helps to know exactly how big its pages are. Is it A4 or Letter? Is every page the same? This tool reads the size of each page and shows it in millimetres, inches and points. It recognises common paper sizes such as A3, A4, A5, Letter, Legal and Tabloid in either orientation, groups pages of the same size together and lists the page numbers, so a document that mixes sizes or has a few rotated pages is easy to spot. It also tells you whether pages are portrait, landscape or square. The file is read in your browser, so nothing is uploaded.
Updated October 2026
How to use the PDF Page Size Checker
- 1Pick your PDF.
- 2Read the summary line: one size or mixed sizes.
- 3Check the table for millimetres, inches and points.
- 4Look at the page list for each size.
- 5Copy the sizes if you need to paste them elsewhere.
Why page size matters
Printers expect a certain paper size, and a mismatch makes the printer scale or crop the page. A PDF made for Letter printed on A4 is slightly too wide in one direction and too short in the other, and the margin may be cut off. Knowing the real size tells you which paper to load and which scaling option to choose.
Mixed sizes are a common problem when files are merged. A scanned page, a presentation slide and a Word page do not usually share a size, and the final file looks uneven when printed or shown on screen.
The page box in a PDF can be set in several ways. The media box is the full sheet, the crop box is what viewers show and the trim box marks where a printer cuts. This tool reports the size that a viewer displays, so it matches what you see on screen. Pages from some design programs also carry bleed outside the trim size, which can make a file a few millimetres larger than the label on the job.
Standard sizes in millimetres
- A3: 297 × 420
- A4: 210 × 297
- A5: 148 × 210
- Letter: 216 × 279 (8.5 × 11 in)
- Legal: 216 × 356 (8.5 × 14 in)
- Tabloid: 279 × 432 (11 × 17 in)
Related tools
If sizes are mixed, make them the same with Resize PDF, trim white space with Crop PDF or add space with the margin tool. Place several pages on one sheet using PDF Pages per Sheet, and turn pages sideways with Rotate PDF. Check a printed page against a ruler if exact size matters to you.
Features
- Size in mm, inches and points
- Recognises A3, A4, A5, Letter, Legal, Tabloid and more
- Groups pages of the same size
- Shows which pages are rotated
- Portrait, landscape or square
- Private, runs in your browser
Frequently asked questions
What are PDF points?
A point is 1/72 of an inch. A4 is 595 by 842 points, and US Letter is 612 by 792 points. PDF files use points internally.
How do I tell A4 from Letter?
A4 is 210 by 297 mm, which is narrower and taller than Letter, 8.5 by 11 inches or 216 by 279 mm. This tool names the paper size for you.
Why does my PDF show a custom size?
The page does not match a standard paper within a few points. This is common for slides, screenshots and web pages saved as PDF.
What if the pages have different sizes?
The tool lists each size with its page numbers. Mixed sizes may print at different scales, so consider making them equal with the Resize PDF tool.
Does rotation change the size?
The tool reports the size as the page appears on screen, with rotation applied. A page rotated by 90 degrees has its width and height swapped.
Are the numbers exact?
They come from the page box in the file. Some PDFs also have crop and trim boxes, which can differ slightly from the media box.
Is my file uploaded?
No.