A3 vs B3
| A3 | B3 | |
|---|---|---|
| Millimetres | 297 × 420 | 353 × 500 |
| Inches | 11.69 × 16.54 | 13.9 × 19.69 |
| Centimetres | 29.7 × 42 | 35.3 × 50 |
| Aspect ratio | 1:1.41 | 1:1.42 |
| Area | 1247.4 cm² | 1765 cm² |
Which is bigger
B3, by 41.5% in area. B3 is 56 mm wider than A3. B3 is 80 mm taller.
Printing one on the other
A A3 page fits inside B3 whole — print it at 100% and you get a 28 mm border down each side and 40 mm top and bottom.
| You want | Set the print scale to | Leaves |
|---|---|---|
| A3 artwork on B3 paper | 118.9% | 0 × 0.8 mm margin |
| B3 artwork on A3 paper | 84% | 0.5 × 0 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: A3 is 1:1.41 and B3 is 1:1.42. 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 0.8 mm of unwanted margin.
Frequently asked questions
What is the difference between A3 and B3?
A3 is 297 × 420 mm and B3 is 353 × 500 mm. B3 is the larger of the two by 41.5% in area.
Can I print A3 on B3?
Yes, at 100% — A3 is smaller on both edges, so it lands inside B3 with a border all round.
Which is bigger, A3 or B3?
B3 — 353 × 500 mm against 297 × 420 mm, which is 41.5% more area.
A3 in full · B3 in full · All size comparisons · All paper sizes