← Back to Blog
Reference4 min read
A4 vs Letter Paper: What's the Difference?
The two most common paper sizes in the world — and why they don't mix.
ISO A4
210 × 297 mm
8.27 × 11.69 inches
Used in 150+ countries worldwide
US Letter
216 × 279 mm
8.5 × 11 inches
Used in USA, Canada, Mexico
Key Differences
A4 and Letter look similar but are not interchangeable. Letter is 6mm wider but 18mm shorter than A4. This means an A4 document will not fit on Letter paper without scaling, and a Letter document will not fit on A4 paper.
Can You Print A4 on Letter Paper?
Yes, but with scaling. In your printer dialog, set the paper size to Letter, then choose "Fit to Printable Area" or "Shrink to Fit." The A4 document will scale down to about 94%. If you need exact physical dimensions, use true A4 paper instead.
Which One Should You Use?
- • A4: If you're outside North America, or working with international documents
- • Letter: If you're in the US, Canada, or Mexico
- • Both: If you need to print photos, use our tool which supports both A4 and Letter paper sizes
Pixel Requirements at 300 DPI
| Paper Size | mm | Pixels @ 300 DPI |
|---|---|---|
| A4 | 210 × 297 mm | 2480 × 3508 px |
| Letter | 216 × 279 mm | 2550 × 3300 px |