A4 is widely used for office documents, manuals, brochures and publications. Its physical dimensions do not depend on the software used: A4 paper measures 210 × 297 mm. What changes is the number of pixels when an image is created at a specific resolution.
For print production, it is important to distinguish between trim size, image resolution and document bleed. These are three separate specifications.
A4 dimensions: 210 × 297 mm, equivalent to 21 × 29.7 cm or approximately 8.27 × 11.69 inches. At 300 ppi, the image is approximately 2480 × 3508 pixels.
A4 paper size conversion table
| Unit | Width | Height |
|---|---|---|
| Millimetres | 210 | 297 |
| Centimetres | 21 | 29.7 |
| Inches | Approx. 8.27 | Approx. 11.69 |
| Pixels at 300 ppi | Approx. 2480 | Approx. 3508 |
| Pixels at 150 ppi | Approx. 1240 | Approx. 1754 |
How many pixels are in an A4 page?
A physical sheet does not have a fixed number of pixels. To calculate it, divide the measurement in millimetres by 25.4 and multiply the result by the required pixels per inch. At 300 ppi, 210 ÷ 25.4 × 300 gives a width of approximately 2480 pixels.
Simply changing the ppi setting in a small file does not restore missing detail. Always check the actual pixel dimensions of photographs.
A4 and US Letter are not the same size
US Letter measures 215.9 × 279.4 mm. It is wider and shorter than A4. If a document designed for Letter is printed on A4, automatic scaling may alter its margins and layout.
How A4 relates to A3 and A5
A3 measures 297 × 420 mm and has roughly twice the area of A4. A5 measures 148 × 210 mm and is approximately half the area. These proportional ISO sizes make it easier to scale layouts while retaining their aspect ratio.
Bleed for an A4 print document
If the job requires 3 mm bleed on every edge, the document including bleed will measure 216 × 303 mm. The final trimmed size remains 210 × 297 mm.
Before exporting: confirm the bleed required by the printer and keep important text away from the trim edge.
What is A4 used for?
A4 is common for business documents, manuals, catalogues, data sheets and some folded leaflets. The best format depends on reading space and whether the piece will be folded or bound. See our brochure printing options for commercial print projects.
Frequently asked questions
Does A4 measure 20 × 30 cm?
No. Its exact dimensions are 21 × 29.7 cm.
Which is larger, A4 or Letter?
They have different proportions: Letter is wider, while A4 is taller.
What are the landscape dimensions?
The dimensions are reversed: 297 mm wide by 210 mm high.
Preparing an A4 job for print? Tell us the dimensions, quantity, material and intended use so that we can review the production options.
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