A0 paper size and dimensions
A0 measures 841 × 1189 mm, which is 84.1 × 118.9 cm or 33.1 × 46.8 inches. Its area is exactly one square metre, and every other A size is made by halving it.
Contents of this page
A0, portrait
841 × 1189mm
- Centimetres
- 84.1 × 118.9 cm
- Inches
- 33.11 × 46.81 in
- Pixels at 300 dpi
- 9933 × 14,043 px
- Points (pt)
- 2384 × 3370 pt
- Area
- 0.9999 m²
- Weight at 80 gsm
- 80 g
A0 is the parent sheet of the whole A series. When Walter Porstmann designed the system in 1922, he did not fix the side lengths. He fixed the area at one square metre, with sides in the ratio 1 to √2. The maths gives 840.9 × 1189.2 mm, rounded to 841 × 1189 mm.
A0 in every unit
| Unit | Width × height |
|---|---|
| Millimetres | 841 × 1189 mm |
| Centimetres | 84.1 × 118.9 cm |
| Metres | 0.841 × 1.189 m |
| Inches | 33.11 × 46.81 in |
| DTP points (1/72 in) | 2384 × 3370 pt |
| Area | 9999.5 cm², or 0.9999 m² |
| Diagonal | 1456.4 mm |
| Aspect ratio | 1 : 1.414 |
Pixels for poster printing
At 300 dpi an A0 poster would need 9933 × 14043 pixels, around 140 megapixels. Hardly any camera delivers that, and you rarely need it. People look at posters from one or two metres away, and 150 dpi (4967 × 7022 pixels) is usually plenty. For photos that people will study up close, 200 dpi is a good compromise.
| Resolution | Pixels | Megapixels | Good for |
|---|---|---|---|
| 72 dpi | 2384 × 3370 px | 8 MP | Screen, preview |
| 100 dpi | 3311 × 4681 px | 15.5 MP | |
| 150 dpi | 4967 × 7022 px | 34.9 MP | Large format, posters seen from a distance |
| 200 dpi | 6622 × 9362 px | 62 MP | |
| 300 dpi | 9933 × 14,043 px | 139.5 MP | Offset and digital print |
Vector artwork such as logos, type and CAD plans has no fixed resolution. Export posters as PDF with vector data wherever you can, and only bring photos up to the pixel count they need.
What A0 is used for
A0 is the classic size for architectural plans and technical drawings. Large-format printers, often called plotters, commonly take 36-inch rolls (914 mm), which fit A0's 841 mm width with some margin.
You see A0 just as often at conferences, where many organisers ask for scientific posters in A0 portrait. Add advertising posters, European film posters and large photo prints.
Plans in A0 are not folded any old way. The German standard DIN 824 describes how to fold technical drawings down to A4 so that the title block stays visible at the bottom right and the plan fits a normal binder.
How many smaller sheets fit on A0?
| Size | Number per A0 sheet |
|---|---|
| A1 | 2 |
| A2 | 4 |
| A3 | 8 |
| A4 | 16 |
| A5 | 32 |
| A6 | 64 |
An A0 sheet of 80 gsm paper therefore weighs almost exactly 80 grams. It is the easiest way to understand paper weight: the gsm figure is the weight of one A0 sheet.
Frames and paper for A0
For A0 posters, aluminium snap frames are popular because you can change the poster without taking the frame off the wall. Glass is heavy and fragile at this size, so acrylic is the more practical choice. Indoor poster paper is usually 135 to 200 gsm; for outdoor use there are weatherproof blueback papers.
No office printer handles A0. Copy shops and online printers print it on a plotter. If you want to split an A0 design, you get two A1 or four A2.
Frequently asked questions
How big is A0 in cm?
A0 is 84.1 cm wide and 118.9 cm tall.
How big is A0 in inches?
33.1 × 46.8 inches.
How many pixels does an A0 poster need?
4967 × 7022 pixels at 150 dpi, 9933 × 14043 pixels at 300 dpi. For posters viewed from a distance, 150 dpi is enough.
How many A4 pages fit on A0?
Exactly 16.
Is there a size bigger than A0?
Yes, the oversizes 2A0 (1189 × 1682 mm) and 4A0 (1682 × 2378 mm), which are rarely used.