A4 vs Letter vs Legal: What's the Difference?
If you've ever opened a document and had it print oddly, or ordered paper that didn't fit your printer tray right, there's a good chance the size was the issue. A4, Letter, and Legal are the three most common paper sizes worldwide, and mixing them up is one of the most common ordering mistakes. Here's exactly how they differ.
Size Comparison at a Glance
| Size | Dimensions (mm) | (mm) Dimensions (inches) | Common Region |
| A4 | 210 x 297 mm | 8.27" x 11.69" | International standard (Europe, Latin America, Asia, Africa) |
| Letter | 216 x 279 mm | 8.5" x 11" | United States, Canada, parts of Latin America |
| Legal | 216 x 356 mm | 8.5" x 14" | United States (legal/contract documents) |
A4 Paper: The International Standard
A4 is part of the ISO 216 international paper size standard and is the default size used across most of the world — including Argentina and the rest of Latin America, Europe, Asia, and Africa. If you're buying printer paper, copy paper, or office paper anywhere outside North America, A4 is almost certainly what you need.
Letter Size: The US Standard
Letter is the default paper size in the United States and Canada, slightly wider and shorter than A4. It's the size you'll see in most US-made printers, templates, and office supply listings by default.
Key difference to know: a document formatted for Letter will not print correctly on A4 paper without adjusting margins, and vice versa — always check which size a template or printer is set to.
Legal Size: For Contracts and Legal Documents
Legal size is longer than both A4 and Letter and is used almost exclusively in the US for legal documents, contracts, and some government forms. Most standard printers can handle Legal size, but it requires switching the paper tray/setting — it's not interchangeable with everyday A4 or Letter printing.
Which Size Do You Need?
- Buying for an office in Argentina, Europe, Asia, or most of the world outside North America? → You need A4.
- Buying for an office in the US or Canada, for everyday printing? → You need Letter.
- Printing contracts or legal documents in the US specifically? → You need Legal.
Frequently Asked Questions
Intended use & functionality of the space
Can I print a Letter-formatted document on A4 paper?
Why does the US use Letter instead of A4?
More A4 Paper Resources
- A4 Paper Brands Compared
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