A3 vs B4
| A3 | B4 | |
|---|---|---|
| Millimetres | 297 × 420 | 250 × 353 |
| Inches | 11.69 × 16.54 | 9.84 × 13.9 |
| Centimetres | 29.7 × 42 | 25 × 35.3 |
| Aspect ratio | 1:1.41 | 1:1.41 |
| Area | 1247.4 cm² | 882.5 cm² |
Which is bigger
A3, by 41.3% in area. A3 is 47 mm wider than B4. A3 is 67 mm taller.
Printing one on the other
A B4 page fits inside A3 whole — print it at 100% and you get a 23.5 mm border down each side and 33.5 mm top and bottom.
| You want | Set the print scale to | Leaves |
|---|---|---|
| A3 artwork on B4 paper | 84% | 0.4 × 0 mm margin |
| B4 artwork on A3 paper | 118.8% | 0 × 0.6 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
Both sheets have the same 1:1.41 proportions, so artwork scales between them without any cropping or extra margin — only the size changes.
Frequently asked questions
What is the difference between A3 and B4?
A3 is 297 × 420 mm and B4 is 250 × 353 mm. A3 is the larger of the two by 41.3% in area.
Can I print A3 on B4?
Not at full size. Scale it to 84% and it fits inside B4 with 0.4 × 0 mm to spare.
Which is bigger, A3 or B4?
A3 — 297 × 420 mm against 250 × 353 mm, which is 41.3% more area.
A3 in full · B4 in full · All size comparisons · All paper sizes