Letter vs A4: the difference explained
A4 is 210 × 297 mm, US Letter 215.9 × 279.4 mm. Letter is 5.9 mm wider and 17.6 mm shorter than A4. In inches that is 8.5 × 11 for Letter against 8.27 × 11.69 for A4, and A4 has about 3 % more area.
Contents of this page
US Letter, portrait
215.9 × 279.4mm
- Centimetres
- 21.59 × 27.94 cm
- Inches
- 8.5 × 11 in
- Pixels at 300 dpi
- 2550 × 3300 px
- Points (pt)
- 612 × 792 pt
- Area
- 0.0603 m²
- Weight at 80 gsm
- 4.83 g
Side by side
| A4 | Letter | Difference | |
|---|---|---|---|
| Width | 210 mm | 215.9 mm | Letter +5.9 mm |
| Height | 297 mm | 279.4 mm | A4 +17.6 mm |
| Inches | 8.27 × 11.69 | 8.5 × 11 | |
| Area | 623.7 cm² | 603.2 cm² | A4 +3.4 % |
| Aspect ratio | 1 : 1.414 | 1 : 1.294 | |
| PDF points | 595 × 842 pt | 612 × 792 pt | |
| Pixels at 300 dpi | 2480 × 3508 | 2550 × 3300 |
What happens when you print
A Letter file on A4 paper: the paper is 5.9 mm narrower than the page. Most printer drivers shrink the page to about 97 % so nothing is cut off, leaving a white strip of a little over 2 cm at the bottom. For most documents that is fine.
An A4 file on Letter paper: now 17.6 mm of height are missing. Without scaling, the footer gets cut off. With “fit to page”, the driver shrinks to about 94 %. Text gets noticeably smaller, and forms that need to print at exact size no longer do.
Look for “choose paper source by PDF page size” or “fit to printable area” in the print dialogue. Many printers in Europe complain about a paper mismatch when a Letter PDF arrives; printing on A4 with “fit to printable area” almost always solves it.
Documents that work on both
If you regularly send documents across the Atlantic, you can set them up to look good on either paper. The shared area is 210 mm wide (like A4) and 279.4 mm tall (like Letter).
- Keep left and right margins of at least 20 mm and top and bottom margins of at least 25 mm.
- Keep anything important out of the bottom 2 cm of an A4 page if it will be printed in the US.
- Export PDFs without a forced paper choice and let the recipient print on their local paper.
- For forms that must fit precisely, provide two versions.
Why are there two standards?
Letter is older than DIN 476, but its exact origin is not documented. A common explanation traces it back to moulds for handmade paper that were about 17 × 22 inches; a quarter of that is 8.5 × 11. US government offices long used a slightly smaller 8 × 10.5 inch sheet and only switched to Letter in the early 1980s. A move to A4 never gained traction, because the metric system is used in the US only in some fields.
Envelopes for Letter
A Letter sheet folded into thirds measures 215.9 × 93.1 mm. It fits a DL envelope (110 × 220 mm), but with only about 2 mm to spare in width. The US No. 10 envelope at 104.8 × 241.3 mm is made for it.
Frequently asked questions
Is A4 bigger than Letter?
A4 is taller and has the larger area (623.7 cm² against 603.2 cm²). Letter is 5.9 mm wider.
Can I print Letter on A4?
Yes. With “fit to page” the page shrinks slightly and leaves a white strip at the bottom.
What percentage to scale A4 to Letter?
About 94 %. The height is the limit: 279.4 mm divided by 297 mm is 94.1 %.
How many pixels is Letter at 300 dpi?
2550 × 3300 pixels.
Which countries use Letter?
Mainly the USA and Canada, and in everyday use also Mexico, Costa Rica, Colombia, Venezuela, Chile and the Philippines.