A4 vs US Letter
A4 is 5.9 mm narrower and 17.6 mm taller than US Letter. Fit-to-page scales are 94% and 97%.
A4 and US Letter side by side
| A4 | US Letter | Difference | |
|---|---|---|---|
| Width | 210 mm (8.27 in) | 215.9 mm (8.5 in) | Letter is 5.9 mm wider |
| Height | 297 mm (11.69 in) | 279.4 mm (11 in) | A4 is 17.6 mm taller |
| Area | 623.7 cm² | 603.2 cm² | A4 is 3.4% larger |
| Shape (long / short) | 1.414 | 1.294 | Letter is squarer |
| Pixels at 300 dpi | 2480 × 3508 | 2550 × 3300 | - |
| Points | 595 × 842 | 612 × 792 | - |
Printing one on the other: scale percentages
A4 and Letter have different shapes, so shrinking one to fit the other leaves a blank strip on one axis. These are the scale factors that make a page just fit.
| Printing | Scale to fit | What happens |
|---|---|---|
| A4 document on Letter paper | 94.1% | Height limits: the page prints 197.6 mm wide by 279.4 mm tall, leaving 18.3 mm of blank width in total (about 9.2 mm each side) |
| Letter document on A4 paper | 97.3% | Width limits: the page prints 210 mm wide by 271.8 mm tall, leaving 25.2 mm of blank height in total |
| Either, no scaling (100%) | 100% | A4 on Letter loses 17.6 mm off the bottom or side; Letter on A4 leaves 17.6 mm blank at the foot and clips 5.9 mm at the sides |
Most print dialogs call this “Fit to page” or “Shrink to fit”. With it on, an A4 PDF prints on Letter at about 94% and a Letter PDF prints on A4 at about 97%.
A safe zone that works on both
The overlap of the two sheets is 210 × 279.4 mm (the narrower width and the shorter height). If you design a form, resume or poster to sit within that rectangle with a margin, it prints without scaling on both A4 and Letter. That is a 8.27 × 11 inch box. Corporate templates for international use often do exactly this.
Where each is used
A4 is the standard in the UK, Europe and most of the world. US Letter is used in the United States and Canada, and in much of Central America and the Philippines; paper sizes by country has the list. Detailed page for each: A4 and US Letter.
Frequently asked questions
Is A4 bigger than Letter?
A4 is 17.6 mm taller but 5.9 mm narrower, and has 3.4% more area.
Can I print A4 on Letter paper?
Yes, but scale it to about 94% to fit the full page, or the bottom 17.6 mm will be cut off.
Can I print Letter on A4 paper?
Yes, at about 97% scale to fit. At 100% the page fits across but is 17.6 mm short at the bottom and 5.9 mm narrower.
What is the common safe area?
A rectangle of 210 x 279.4 mm fits both sheets.
Is Letter wider than A4?
Yes, by 5.9 mm.