A9 vs JIS B9
| A9 | JIS B9 | |
|---|---|---|
| Millimetres | 37 × 52 | 45 × 64 |
| Inches | 1.46 × 2.05 | 1.77 × 2.52 |
| Centimetres | 3.7 × 5.2 | 4.5 × 6.4 |
| Aspect ratio | 1:1.41 | 1:1.42 |
| Area | 19.2 cm² | 28.8 cm² |
Which is bigger
A9 and JIS B9 carry the same number and are not the same sheet. The Japanese B series is defined by area — JIS B0 is 1.5 square metres where A0 is 1 — so a JIS B sheet is half again the area of the A sheet of the same number, and about 22% longer on each edge. The number tells you where a sheet sits in its own series and nothing about which standard it belongs to.
JIS B9, by 49.7% in area. JIS B9 is 8 mm wider than A9. JIS B9 is 12 mm taller.
Printing one on the other
A A9 page fits inside JIS B9 whole — print it at 100% and you get a 4 mm border down each side and 6 mm top and bottom.
| You want | Set the print scale to | Leaves |
|---|---|---|
| A9 artwork on JIS B9 paper | 121.6% | 0 × 0.8 mm margin |
| JIS B9 artwork on A9 paper | 81.3% | 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 JIS B9 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 A9 and JIS B9?
A9 is 37 × 52 mm and JIS B9 is 45 × 64 mm. JIS B9 is the larger of the two by 49.7% in area.
Can I print A9 on JIS B9?
Yes, at 100% — A9 is smaller on both edges, so it lands inside JIS B9 with a border all round.
Which is bigger, A9 or JIS B9?
JIS B9 — 45 × 64 mm against 37 × 52 mm, which is 49.7% more area.
Related comparisons
A9 in full · JIS B9 in full · All size comparisons · All paper sizes