ISO A · ISO 216
A4 paper size
The standard office and document paper size across most of the world, with an aspect ratio that stays constant when the sheet is halved.
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A4 dimensions in every unit
In portrait orientation, width comes first: 210 mm × 297 mm. Rotate the sheet for landscape orientation and the same measurements reverse.
| Unit | Width | Height |
|---|---|---|
| Millimeters | 210 mm | 297 mm |
| Centimeters | 21 cm | 29.7 cm |
| Inches | 8.27 in | 11.69 in |
| Points | 595.3 pt | 841.9 pt |
Digital artwork
A4 pixel dimensions by DPI
Pixel dimensions depend on output resolution. These values describe the trimmed page only and do not include printer bleed.
| Resolution | Pixel width | Pixel height | Typical use |
|---|---|---|---|
| 72 DPI | 595 px | 842 px | Screen preview |
| 96 DPI | 794 px | 1,123 px | Screen preview |
| 150 DPI | 1,240 px | 1,754 px | Draft print |
| 300 DPI | 2,480 px | 3,508 px | Quality print |
| 600 DPI | 4,961 px | 7,016 px | High-detail source |
Proportion & comparison
How A4 relates to nearby sizes
A4 is 5.9 mm narrower and 17.6 mm taller than US Letter. Scaling without checking margins can move line breaks or clip headers and footers.
- Portrait ratio
- 1 : 1.4143
- Area
- 0.0624 m²
- Orientation
- 210 × 297 mm
Works well for
Common A4 uses
- Office documents
- Letters and reports
- Forms
- Home and school printing
Check before using
Where it can go wrong
- US forms fixed to Letter
- Legal-length contracts
- 11 × 17 inch layouts
Regional & printer note
Will a printer recognize A4?
The default document size in most countries outside the United States, Canada, and parts of Latin America.
Always match the document size, print-driver size, paper tray, and physical sheet. A driver can silently scale a page even when the preview looks correct.
Measurement source
Checked against the defining standard
Paper Size Lab converts the stored millimeter measurements mathematically; it does not round-trip between units. The underlying sheet family is referenced to the standards organization below.
Read ISO 216:2007Questions people ask
A4 paper FAQ
What are the dimensions of A4 paper?
A4 measures 210 × 297 millimeters, 21 × 29.7 centimeters, or 8.27 × 11.69 inches in portrait orientation.
How many pixels is A4 at 300 DPI?
A4 is 2480 × 3508 pixels at 300 DPI before adding bleed.
Is A4 the same as US Letter?
A4 is 5.9 mm narrower and 17.6 mm taller than US Letter. Scaling without checking margins can move line breaks or clip headers and footers.
What is A4 commonly used for?
A4 is commonly used for office documents, letters and reports, forms, home and school printing. Printer, postal, and finishing requirements still vary.