Toolman

A9 vs B10

A9B10
Millimetres37 × 5231 × 44
Inches1.46 × 2.051.22 × 1.73
Centimetres3.7 × 5.23.1 × 4.4
Aspect ratio1:1.411:1.42
Area19.2 cm²13.6 cm²

Which is bigger

A9, by 41.1% in area. A9 is 6 mm wider than B10. A9 is 8 mm taller.

Printing one on the other

A B10 page fits inside A9 whole — print it at 100% and you get a 3 mm border down each side and 4 mm top and bottom.

You wantSet the print scale toLeaves
A9 artwork on B10 paper83.8%0 × 0.4 mm margin
B10 artwork on A9 paper118.2%0.4 × 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: A9 is 1:1.41 and B10 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 0.4 mm of unwanted margin.

Frequently asked questions

What is the difference between A9 and B10?

A9 is 37 × 52 mm and B10 is 31 × 44 mm. A9 is the larger of the two by 41.1% in area.

Can I print A9 on B10?

Not at full size. Scale it to 83.8% and it fits inside B10 with 0 × 0.4 mm to spare.

Which is bigger, A9 or B10?

A9 — 37 × 52 mm against 31 × 44 mm, which is 41.1% more area.

A9 in full · B10 in full · All size comparisons · All paper sizes