The common paper sizes
| Size | Millimetres | Inches | Where it is used |
|---|---|---|---|
| A4 | 210 × 297 mm | 8.27 × 11.69 in | UK, Europe, Australia, most of Asia |
| Letter | 216 × 279 mm | 8.5 × 11 in | US, Canada, Philippines |
| Legal | 216 × 356 mm | 8.5 × 14 in | US and Canadian legal documents |
| A3 | 297 × 420 mm | 11.69 × 16.54 in | Posters, drawings, spreadsheets |
| A5 | 148 × 210 mm | 5.83 × 8.27 in | Notebooks, planners, leaflets |
| Tabloid | 279 × 432 mm | 11 × 17 in | US posters and tabloid printing |
ISO A series vs US sizes
The ISO A series halves each size: A3 is two A4 sheets, A4 is two A5 sheets. Every A size has the same aspect ratio (1:√2), so a page can be enlarged or reduced without changing its shape. US sizes do not share one ratio: Letter is 8.5 × 11 in and Legal is 8.5 × 14 in, so content does not scale as cleanly between them.
Choosing a size
- Everyday printing: Letter in the US, Canada and the Philippines; A4 almost everywhere else.
- School and office: A4 or Letter, matching the printer and binders already in use.
- Posters and drawings: A3 or Tabloid for a larger sheet without a plotter.
- Notebooks and planners: A5 is the common travel size; half-Letter also works.
Printing at the right size
Always choose the paper size in the generator before downloading a PDF. Then print at Actual size or 100%. “Fit to page” changes the dimensions and makes grids and handwriting guides come out at the wrong scale. Read the full A4 vs Letter comparison for the differences in detail, or start with a blank PDF in any size.
In practice
An office in Canada orders Letter paper, while a partner in the UK sends A4 PDFs. Before printing a shared document, check the page size in the PDF and the paper in the tray. The chart turns a vague “A4-ish” into exact millimetres and inches.
Common mistakes
| Problem | Usually because | What to do |
|---|---|---|
| A4 content is clipped on Letter | The page sizes differ | Print the PDF at its own size or re-export for Letter |
| The printer ignores the selected size | The tray is set to another size | Match the tray guide and the driver setting |
| Envelopes or cards come out wrong | Using a standard paper preset | Create a custom size from the chart |
Blank PDF 
Lined paper 
Graph paper