A4 vs Letter
| A4 | Letter | |
|---|---|---|
| Millimetres | 210 × 297 | 215.9 × 279.4 |
| Inches | 8.27 × 11.69 | 8.5 × 11 |
| Centimetres | 21 × 29.7 | 21.6 × 27.9 |
| Aspect ratio | 1:1.41 | 1:1.29 |
| Area | 623.7 cm² | 603.2 cm² |
Which is bigger
A4, by 3.4% in area. Letter is 5.9 mm wider than A4. A4 is 17.6 mm taller.
Printing one on the other
Neither sheet fits inside the other at full size: Letter is the wider of the two while A4 is the taller, so each overruns the other on one edge. Whichever way you go, something has to scale or crop.
| You want | Set the print scale to | Leaves |
|---|---|---|
| A4 artwork on Letter paper | 94.1% | 18.3 × 0 mm margin |
| Letter artwork on A4 paper | 97.3% | 0 × 25.2 mm margin |
These are the numbers for the "custom scale" box in a print dialog. "Fit to page" computes the same thing, but knowing the figure tells you in advance whether the result will look deliberate or accidental.
Why the shapes matter
The proportions differ: A4 is 1:1.41 and Letter is 1:1.29. That difference is why a layout moved between them never quite lines up — scale it to fit one edge and the other is left with 18.3 mm of unwanted margin.
Frequently asked questions
What is the difference between A4 and Letter?
A4 is 210 × 297 mm and Letter is 215.9 × 279.4 mm. A4 is the larger of the two by 3.4% in area.
Can I print A4 on Letter?
Not at full size. Scale it to 94.1% and it fits inside Letter with 18.3 × 0 mm to spare.
Which is bigger, A4 or Letter?
A4 — 210 × 297 mm against 215.9 × 279.4 mm, which is 3.4% more area.
A4 in full · Letter in full · All size comparisons · All paper sizes