A4 is the standard paper size in the UK and most of the world. The exact dimensions are 210 × 297 mm — that's 21 × 29.7 cm, or 8.27 × 11.69 inches. Here's everything that number affects, from Word documents to pixel dimensions for design work.
A4 dimensions at a glance
| Unit | A4 dimensions (width × height) |
|---|---|
| Millimetres | 210 × 297 mm |
| Centimetres | 21 × 29.7 cm |
| Inches | 8.27 × 11.69 in |
| Pixels at 300 DPI (print) | 2480 × 3508 px |
| Pixels at 72 DPI (screen) | 595 × 842 px |
Where A4 comes from
A4 is part of the international ISO 216 "A series", where every size is half the one above it: two A4 sheets make an A3, and half an A4 is an A5. The proportions (1:√2) stay identical at every size, which is why documents scale cleanly between sizes. See our full UK paper sizes chart for A0 through A6.
A4 vs US Letter
The US standard, Letter, is 8.5 × 11 inches (216 × 279 mm) — slightly wider and shorter than A4. This matters when you print an American template on UK paper: text near the edges can clip or shift. If a document looks wrong, check the page size in your export settings and set it to A4 before saving the PDF. Our guide to saving a PDF for printing walks through it.
A4 in pixels for design work
For print-quality artwork, work at 300 DPI: an A4 canvas is 2480 × 3508 pixels. Anything much lower will look soft on paper — a common reason a design that looked sharp on screen prints blurry. For screen-only mockups, 595 × 842 px (72 DPI) matches A4 proportions.
Common A4 questions
Is A4 the same as "letter size" in the UK?
In the UK, "letter paper" colloquially means A4 — but if software offers a "Letter" page size, that's the US format. Always pick A4 explicitly.
What weight of A4 paper is normal?
Standard office A4 is 80gsm. Higher weights (100–120gsm) feel more substantial and suit CVs, certificates, and client-facing documents.
What fits in what envelope?
A4 folded in half fits a C5 envelope; folded in thirds it fits a DL envelope; flat A4 needs a C4 envelope.
Printing A4 documents without a printer
A4 is what we print all day at printle. Upload your PDF, choose black & white (from 15p per page) or colour (from 32p), and we'll print and post it anywhere in the UK — same-day dispatch on working days before 2 PM, free delivery over £10. See our A4 printing online guide for prices in detail.