A4 Paper Size in cm, mm & Inches
A4 is the world's most common paper size — used in 160+ countries for documents, printing, and design. It is defined by the ISO 216 international standard.
Proportional size comparison — A3 = 2× A4, A4 = 2× A5
ISO A-Series & US Paper Sizes
| Size | mm | cm | inches | px @ 96ppi |
|---|---|---|---|---|
| A3 | 297 × 420 | 29.7 × 42.0 | 11.69 × 16.54 | 1123 × 1587 |
| A4 | 210 × 297 | 21.0 × 29.7 | 8.27 × 11.69 | 794 × 1123 |
| A5 | 148 × 210 | 14.8 × 21.0 | 5.83 × 8.27 | 559 × 794 |
| A6 | 105 × 148 | 10.5 × 14.8 | 4.13 × 5.83 | 397 × 559 |
| A7 | 74 × 105 | 7.4 × 10.5 | 2.91 × 4.13 | 280 × 397 |
| US Letter | 216 × 279 | 21.6 × 27.9 | 8.5 × 11.0 | 816 × 1056 |
| US Legal | 216 × 356 | 21.6 × 35.6 | 8.5 × 14.0 | 816 × 1344 |
| US Tabloid | 279 × 432 | 27.9 × 43.2 | 11.0 × 17.0 | 1056 × 1632 |
A4 in Pixels at Different DPI
| Resolution | Width (px) | Height (px) |
|---|---|---|
| 72 DPI (PDF legacy) | 595 | 842 |
| 96 PPI (web standard) | 794 | 1123 |
| 150 DPI (medium print) | 1240 | 1754 |
| 300 DPI (high-res print) | 2480 | 3508 |
Frequently Asked Questions
What is the size of A4 paper in cm?
A4 paper is 21.0 cm wide and 29.7 cm tall (210 mm × 297 mm). It is the most widely used paper size in the world, defined by the ISO 216 standard.
What is A4 size in inches?
A4 paper is 8.27 inches wide and 11.69 inches tall. This is slightly narrower and taller than US Letter paper (8.5 × 11 inches).
What is A4 in pixels?
At 96 PPI (web standard), A4 is 794 × 1123 pixels. At 72 PPI (print legacy), it is 595 × 842 pixels. At 300 PPI (high-resolution print), it is 2480 × 3508 pixels.
What is the difference between A4 and US Letter?
US Letter (8.5 × 11 in) is slightly wider but shorter than A4 (8.27 × 11.69 in). A4 is taller and narrower. Most of the world uses A4; the US, Canada, and Mexico use Letter.
How does the ISO A-series paper sizing work?
Each A-size is exactly half the area of the one above it. A3 folded in half = A4. A4 folded in half = A5. All sizes share the same aspect ratio (1:√2 ≈ 1:1.414), so scaling is always consistent.
What is A4 size at 300 DPI for printing?
At 300 DPI (dots per inch, equivalent to PPI for printing), A4 is 2480 × 3508 pixels. This is the standard resolution for high-quality print output.