A1 paper size
594 × 841 mm
23.39 × 33.11 inches · 59.4 × 84.1 cm · aspect ratio 1:1.42
A1 size is 594 × 841 mm. Those are the A1 dimensions a printer works to; the same sheet in centimetres, inches, points and pixels is below.
What A1 is for
A1 is the size most large-format plotters treat as their default roll width, and the standard for exhibition boards and technical drawings that need to be read standing up. At 594 × 841 mm it is exactly half an A0 and exactly two A2 sheets. If you are printing a poster to be read from about a metre away, A1 carries body text at 18–24 pt comfortably; A0 is for a room.
A1 dimensions in every unit
| Unit | Width | Height |
|---|---|---|
| Millimetres | 594 mm | 841 mm |
| Centimetres | 59.4 cm | 84.1 cm |
| Inches | 23.39 in | 33.11 in |
| Points (PostScript) | 1684 pt | 2384 pt |
A1 in pixels
Pixel dimensions depend entirely on the resolution you are working at — there is no single "pixel size" for a sheet of paper. A1 size in pixels has every resolution, with file sizes and canvas setup.
| Resolution | Pixels | Use |
|---|---|---|
| 72 DPI | 1684 × 2384 | Screen preview only — far too coarse to print |
| 150 DPI | 3508 × 4967 | Draft printing, internal documents |
| 300 DPI | 7016 × 9933 | The standard for commercial print |
| 600 DPI | 14031 × 19866 | 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 A1 relates to the rest of the series
A1 is A0 halved once. 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 2 sheets of A1 exactly one sheet of A0, with nothing left over. The area works out at 0.5 m², since A0 is defined as one square metre.
Against the sheet most people picture: one of these holds 8 A4 sheets.
Scaling to the next size up or down is a factor of √2 ≈ 1.414 on each edge, so enlarging A1 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 A1
Half of A0. Common for posters, technical drawings and exhibition boards.
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 |
| 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 |
| A9 | 37 × 52 mm | 1.46 × 2.05 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 A1 in mm?
594 × 841 mm.
What size is A1 in inches?
23.39 × 33.11 inches.
What size is A1 in pixels?
There is no single answer — it depends on resolution. At the print standard of 300 DPI it is 7016 × 9933 pixels; at 72 DPI it is only 1684 × 2384.