A3 vs C3
| A3 | C3 | |
|---|---|---|
| Millimetres | 297 × 420 | 324 × 458 |
| Inches | 11.69 × 16.54 | 12.76 × 18.03 |
| Centimetres | 29.7 × 42 | 32.4 × 45.8 |
| Aspect ratio | 1:1.41 | 1:1.41 |
| Area | 1247.4 cm² | 1483.9 cm² |
Which is bigger
C3, by 19% in area. C3 is 27 mm wider than A3. C3 is 38 mm taller.
Printing one on the other
A A3 page fits inside C3 whole — print it at 100% and you get a 13.5 mm border down each side and 19 mm top and bottom.
| You want | Set the print scale to | Leaves |
|---|---|---|
| A3 artwork on C3 paper | 109% | 0.1 × 0 mm margin |
| C3 artwork on A3 paper | 91.7% | 0 × 0.2 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
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 C3?
A3 is 297 × 420 mm and C3 is 324 × 458 mm. C3 is the larger of the two by 19% in area.
Can I print A3 on C3?
Yes, at 100% — A3 is smaller on both edges, so it lands inside C3 with a border all round.
Which is bigger, A3 or C3?
C3 — 324 × 458 mm against 297 × 420 mm, which is 19% more area.
A3 in full · C3 in full · All size comparisons · All paper sizes