A4 size in pixels: 2480 × 3508 at 300 dpi (and every other resolution)
A4 is 210 × 297 mm. In pixels that is 2480 × 3508 at 300 dpi, 1240 × 1754 at 150 dpi and 595 × 842 at 72 dpi. Here is the full table with A3, A5, A6 and US Letter, and how to calculate any size yourself.
A sheet of A4 paper measures 210 × 297 millimetres — 8.27 × 11.69 inches. How many pixels that is depends entirely on the resolution you print or display at: multiply the size in inches by the dots per inch. At the 300 dpi that print shops expect, an A4 page is 2480 × 3508 pixels; at 150 dpi it is 1240 × 1754; at the classic screen value of 72 dpi it is 595 × 842, which is also the size in PDF points.
The same formula — pixels = millimetres ÷ 25.4 × dpi — gives every other paper size. The table below lists A3, A4, A5, A6 and US Letter at the five resolutions you are likely to meet.
Paper sizes in pixels
| Format | 72 dpi | 96 dpi | 150 dpi | 300 dpi | 600 dpi |
|---|---|---|---|---|---|
| A3 (297 × 420 mm) | 842 × 1191 | 1123 × 1587 | 1754 × 2480 | 3508 × 4961 | 7016 × 9921 |
| A4 (210 × 297 mm) | 595 × 842 | 794 × 1123 | 1240 × 1754 | 2480 × 3508 | 4961 × 7016 |
| A5 (148 × 210 mm) | 420 × 595 | 559 × 794 | 874 × 1240 | 1748 × 2480 | 3496 × 4961 |
| A6 (105 × 148 mm) | 298 × 420 | 397 × 559 | 620 × 874 | 1240 × 1748 | 2480 × 3496 |
| US Letter (215.9 × 279.4 mm) | 612 × 792 | 816 × 1056 | 1275 × 1650 | 2550 × 3300 | 5100 × 6600 |
Rounded to whole pixels. Design tools that measure in points use 72 per inch, so “A4 at 72 dpi” (595 × 842) is also the A4 page size in PDF and most layout software.
Which resolution to use for A4
- 300 dpi (2480 × 3508 px) — anything printed and read up close: documents, flyers, photo pages, scans meant for archiving.
- 150 dpi (1240 × 1754 px) — drafts, posters seen from a distance, internal documents; a quarter of the pixels of 300 dpi.
- 96 dpi (794 × 1123 px) — the CSS reference resolution; what a browser considers an A4 page when printing HTML.
- 72 dpi (595 × 842 px) — the size in points; use it when a layout program asks for page dimensions.
- 600 dpi (4960 × 7016 px) — line art, small type and scans that will be enlarged; rarely needed for photos.
A4 with bleed and margins
Printers usually ask for 3 mm of bleed on each side, which makes the file 216 × 303 mm — 2551 × 3579 pixels at 300 dpi. Keep text at least 3–5 mm inside the trimmed edge. If you are exporting from an image editor, set the canvas to the bleed size and let the printer trim; if you are supplying a PDF, the bleed is added by the layout tool.
Scanning and photographing A4 documents
A 300 dpi scan of an A4 page produces a 2480 × 3508 image of about 8.7 megapixels — enough to reprint at full quality and to run OCR reliably. A phone photo of a document is typically 12 megapixels but rarely evenly sharp; 200 dpi (1654 × 2339) is a practical target for readable archives. To turn several scans into one document, the image-to-PDF tool assembles pages at the exact A4 size locally.
Calculating any size yourself
Divide the length in millimetres by 25.4 to get inches, then multiply by the resolution. A4 width: 210 ÷ 25.4 = 8.268 in × 300 = 2480 px. For half a page, use A5 (148 × 210 mm); for double, A3 (297 × 420 mm) — each A size is the previous one halved along the long edge, so the pixel counts follow the same pattern. The converter above does the arithmetic for any unit and resolution.
Frequently asked questions
2480 × 3508 pixels (portrait). Landscape is simply 3508 × 2480.
595 × 842 pixels — the same numbers as A4 in PDF points, which is why layout tools show them.
300 dpi, so 2480 × 3508 pixels. Add 3 mm bleed per side (2551 × 3579 px) if the printer requests it.
No. US Letter is 8.5 × 11 inches (215.9 × 279.4 mm) — slightly wider and shorter than A4. At 300 dpi it is 2550 × 3300 pixels.