ARCH B vs C3
| ARCH B | C3 | |
|---|---|---|
| Millimetres | 304.8 × 457.2 | 324 × 458 |
| Inches | 12 × 18 | 12.76 × 18.03 |
| Centimetres | 30.5 × 45.7 | 32.4 × 45.8 |
| Aspect ratio | 1:1.5 | 1:1.41 |
| Area | 1393.5 cm² | 1483.9 cm² |
Which is bigger
C3, by 6.5% in area. C3 is 19.2 mm wider than ARCH B. C3 is 0.8 mm taller.
Printing one on the other
A ARCH B page fits inside C3 whole — print it at 100% and you get a 9.6 mm border down each side and 0.4 mm top and bottom.
| You want | Set the print scale to | Leaves |
|---|---|---|
| ARCH B artwork on C3 paper | 100.2% | 18.7 × 0 mm margin |
| C3 artwork on ARCH B paper | 94.1% | 0 × 26.3 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: ARCH B is 1:1.5 and C3 is 1:1.41. 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 18.7 mm of unwanted margin.
Frequently asked questions
What is the difference between ARCH B and C3?
ARCH B is 304.8 × 457.2 mm and C3 is 324 × 458 mm. C3 is the larger of the two by 6.5% in area.
Can I print ARCH B on C3?
Yes, at 100% — ARCH B is smaller on both edges, so it lands inside C3 with a border all round.
Which is bigger, ARCH B or C3?
C3 — 324 × 458 mm against 304.8 × 457.2 mm, which is 6.5% more area.
ARCH B in full · C3 in full · All size comparisons · All paper sizes