Page numbers
How to Add Page Numbers to a PDF
Noticing there are no page numbers only after the pages are printed and stapled is a familiar experience. The hard part is not adding them but adding them correctly — position, start value, and format all depend on what the document is for.
Choosing a position
Six options are available: three alignments at the top and three at the bottom. Pick based on how the printed document gets used.
| Position | Best for |
|---|---|
| Bottom centre | The default choice; does not collide with headers in duplex printing |
| Bottom left / right | Pages that already carry footer text, so the number stays clear of it |
| Top centre | Documents with captions or tables at the bottom that must not be obscured |
| Top left / right | Academic material and contract appendices, usually paired with a header |
The margin is fixed at 24pt (about 8.5mm) and the size ranges from 6 to 36pt, defaulting to 10pt. On documents with narrow margins the number may overlap body text — drop to 7-8pt, or move it to the header.
Three number formats
- Plain (1, 2, 3) — the universal default; what most journals and contracts expect
- Page N (Page 1) — reads more naturally in prose
- Page N / M (Page 1 / 8) — reveals the total immediately, useful when completeness matters
Note that M is the current document's page count, not the size of a range you selected. If you extract pages first and then number them, M counts the extracted document — usually what you want, but worth confirming.
Starting page: continuing an existing sequence
If a 50-page document was split for processing and the second half must continue rather than restart, set the starting page to 26. The default is 1. Starting at 0 is possible but essentially never appropriate for formal material.
Headers and footers: the more useful layer
Alongside the number you can set optional header text and footer text. The header is centred at the top of the page, the footer centred at the bottom, both sharing the same 24pt margin as the page number.
Typical uses: "Company Name — Confidential" in the header, a document number or version in the footer. When a PDF will circulate through several rounds of review, stamping a version and date in the footer eliminates most "which version is this?" email threads.
Will numbering damage existing content?
It does not erase body text, but the number is drawn on top of the page content. Where something already exists at that spot — text or an image — the two will overlap.
Check two or three pages first. Scans usually have generous white margins and are safe; web-exported PDFs often run edge to edge, in which case the position choice matters more.
How the major tools do it
Adobe Acrobat Pro: Edit PDF → Headers and Footers, with position, format, size, and the option to start numbering from a given page. Custom prefixes such as "Page 1 of 8" are supported.
Adobe Reader: cannot add page numbers; it only displays existing ones.
Word / WPS: numbering added natively in Word ends up as text boxes in the exported PDF, which can be selected or misaligned in other readers. Tools produce cleaner output.
UniPagePDF (browser): choose Page Numbers, set position, start, format, size, and any header/footer text, then export. Runs locally.
Common mistakes
- Making the number huge. Page numbers are a locating aid; oversized numbers disrupt reading. Around 10pt is the norm.
- Letting the number collide with a watermark. If a document gets both, keep the two layers in separate regions.
- Expecting numbering to reduce file size. It does not. Use compression for that.