A9 paper size
37 × 52 mm
1.46 × 2.05 inches · 3.7 × 5.2 cm · aspect ratio 1:1.41
A9 size is 37 × 52 mm. Those are the A9 dimensions a printer works to; the same sheet in centimetres, inches, points and pixels is below.
What A9 is for
A9, 37 × 52 mm, is small enough that it is rarely specified by name — the things made at this size are labels and tokens, usually cut from a larger sheet rather than ordered as A9. It is the smallest A size that will hold a readable line of text.
A9 dimensions in every unit
| Unit | Width | Height |
|---|---|---|
| Millimetres | 37 mm | 52 mm |
| Centimetres | 3.7 cm | 5.2 cm |
| Inches | 1.46 in | 2.05 in |
| Points (PostScript) | 105 pt | 147 pt |
A9 in pixels
Pixel dimensions depend entirely on the resolution you are working at — there is no single "pixel size" for a sheet of paper. A9 size in pixels has every resolution, with file sizes and canvas setup.
| Resolution | Pixels | Use |
|---|---|---|
| 72 DPI | 105 × 147 | Screen preview only — far too coarse to print |
| 150 DPI | 219 × 307 | Draft printing, internal documents |
| 300 DPI | 437 × 614 | The standard for commercial print |
| 600 DPI | 874 × 1228 | Fine detail, line art, archival scanning |
Setting up a print document? Use 300 DPI and add 3 mm of bleed on every edge unless your printer specifies otherwise.
How A9 relates to the rest of the series
A9 is A0 halved 9 times. Halving a sheet across its longer side is what generates the next size down, and because the sides are in a 1:√2 ratio the proportions survive every fold — which is the entire reason the series exists.
That makes 512 sheets of A9 exactly one sheet of A0, with nothing left over. The area works out at 0.001953 m², since A0 is defined as one square metre.
Against the sheet most people picture: 32 of these fit on one A4.
Scaling to the next size up or down is a factor of √2 ≈ 1.414 on each edge, so enlarging A9 to the next size is 141% on a photocopier and reducing it is 71%. Those two numbers are on the preset buttons of most copiers for exactly this reason, and they are the same for every size in the series.
About A9
Rarely used outside of very small labels.
Why A sizes halve so neatly
The A series is built on a 1:√2 ratio — approximately 1:1.414. That proportion has a unique property: cut the sheet in half across its long side and the two halves keep exactly the same proportions. This is why two A4 sheets make an A3, why scaling A4 artwork to A3 needs no cropping, and why photocopiers have a single "A4 → A3" button that just works.
Other ISO A series sizes
| Size | Millimetres | Inches |
|---|---|---|
| A0 | 841 × 1189 mm | 33.11 × 46.81 in |
| A1 | 594 × 841 mm | 23.39 × 33.11 in |
| A2 | 420 × 594 mm | 16.54 × 23.39 in |
| A3 | 297 × 420 mm | 11.69 × 16.54 in |
| A4 | 210 × 297 mm | 8.27 × 11.69 in |
| A5 | 148 × 210 mm | 5.83 × 8.27 in |
| A6 | 105 × 148 mm | 4.13 × 5.83 in |
| A7 | 74 × 105 mm | 2.91 × 4.13 in |
| A8 | 52 × 74 mm | 2.05 × 2.91 in |
| A10 | 26 × 37 mm | 1.02 × 1.46 in |
| Super A3 | 329 × 483 mm | 12.95 × 19.02 in |
Frequently asked questions
What size is A9 in mm?
37 × 52 mm.
What size is A9 in inches?
1.46 × 2.05 inches.
What size is A9 in pixels?
There is no single answer — it depends on resolution. At the print standard of 300 DPI it is 437 × 614 pixels; at 72 DPI it is only 105 × 147.