A4 Paper Sizes: Dimensions in Inches, CM, MM & Pixels
A4 paper size measures 210 × 297 mm (8.27 × 11.69 inches or 21 × 29.7 cm). It’s the world’s most common paper format based on the ISO 216 standard.
This guide explains every important A4 paper size conversion, compares it with US Letter, shows pixel dimensions for different DPI settings, and answers the most common questions.
📄 What Is A4 Paper Size?
A4 belongs to the ISO 216 paper system used in more than 200 countries. It is the default page size in Microsoft Word, Google Docs, Adobe Acrobat, and most design software outside North America.
| Unit | Value |
|---|---|
| Millimeters | 210 × 297 mm |
| Centimeters | 21 × 29.7 cm |
| Inches | 8.27 × 11.69 in |
| Pixels (300 DPI) | 2480 × 3508 px |
| Aspect Ratio | 1 : √2 |
🖥️ A4 Paper Size in Inches, CM, MM & Pixels
The physical dimensions never change. Only the pixel resolution changes according to your chosen DPI (Dots Per Inch).
| DPI | Width | Height | Best For |
|---|---|---|---|
| 72 DPI | 595 px | 842 px | Web previews |
| 96 DPI | 794 px | 1123 px | Computer screens |
| 150 DPI | 1240 px | 1754 px | Draft printing |
| 300 DPI | 2480 px | 3508 px | Professional printing |
📑 A4 vs Letter Size
| Paper | Dimensions | Difference |
|---|---|---|
| A4 | 8.27 × 11.69 in | Narrower & Taller |
| Letter | 8.5 × 11 in | Wider & Shorter |
The difference is only about a quarter inch, but it can affect page margins and document layouts during printing.
📚 A4 Compared with A3, A5, A6 & B5
A3
297 × 420 mm
Bigger than A4
A4
210 × 297 mm
Standard Document Size
A5
148 × 210 mm
Half of A4
B5
176 × 250 mm
Between A4 & A5
🇺🇸 A4 Paper Alternatives in the US
Letter
8.5 × 11″
Everyday office documents.
Legal
8.5 × 14″
Contracts and legal paperwork.
Tabloid
11 × 17″
Large spreadsheets and posters.
❓ Frequently Asked Questions
Is A4 the same as 8.5 × 11 paper?
No. A4 is narrower and taller than US Letter paper.
What is A4 size in cm?
21 × 29.7 cm.
Are A4 and A5 the same?
No. A5 is exactly half the size of A4.
Is 11 × 17 the same as A4?
No. It is closer to A3.
Which is bigger: B5, A5 or A4?
A4 is the largest, followed by B5, then A5.
What are A4 paper alternatives?
Letter, Legal and Tabloid are the closest US paper sizes.
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