A0 Paper Size: 84.1 × 118.9 cm

A0 measures 84.1 × 118.9 cm — 841 × 1189 mm, or 33.1 × 46.8 inches. It is the largest sheet in the ISO 216 A series and the sheet every other A size is cut from. At 300 DPI an A0 print needs 9933 × 14043 pixels.

A0 Dimensions in Every Unit

Unit Width Height Notes
Centimetres 84.1 cm 118.9 cm The figure most people are looking for
Millimetres 841 mm 1189 mm The official ISO 216 definition
Inches 33.1 in 46.8 in Rounded to one decimal place
Metres 0.841 m 1.189 m Area 0.999 m² — effectively 1 m²
Feet 2 ft 9.1 in 3 ft 10.8 in Roughly 2.76 × 3.90 ft
Points (PDF) 2384 pt 3370 pt PDF page size at 72 points per inch

A0 Size in Pixels by DPI

Resolution Pixel Dimensions Megapixels Best For
72 DPI 2384 × 3370 px 8.0 MP Screen preview and PDF layout only
100 DPI 3311 × 4681 px 15.5 MP Banners viewed from several metres away
150 DPI 4967 × 7022 px 34.9 MP Large posters read at arm's length or further
200 DPI 6622 × 9362 px 62.0 MP Exhibition boards with body text
300 DPI 9933 × 14043 px 139.5 MP Full print standard — fine detail and small type

How A0 Compares to A1, A2, A3 and A4

Size Centimetres Millimetres Fraction of A0
A0 84.1 × 118.9 cm 841 × 1189 mm 1 sheet
A1 59.4 × 84.1 cm 594 × 841 mm 1⁄2 of A0
A2 42.0 × 59.4 cm 420 × 594 mm 1⁄4 of A0
A3 29.7 × 42.0 cm 297 × 420 mm 1⁄8 of A0
A4 21.0 × 29.7 cm 210 × 297 mm 1⁄16 of A0
A5 14.8 × 21.0 cm 148 × 210 mm 1⁄32 of A0

Understanding the A0 Sheet

Why A0 Is 841 × 1189 mm

ISO 216 starts from two rules: the sheet must have an area of one square metre, and its sides must be in the ratio 1:√2. Solve those together and you get 841 × 1189 mm — an area of 0.999 m² once rounded to whole millimetres. Every other A size then comes from folding that sheet in half along its long edge, which is why the proportions never change as the numbers shrink.

How Many A4 Sheets Fit in an A0?

Sixteen. A0 halves into two A1s, four A2s, eight A3s, and sixteen A4s. That is a useful sanity check when a printer quotes by the A0 sheet: an A0 poster costs the same in paper as sixteen A4 pages.

What A0 Is Used For

  • Academic and conference posters — A0 portrait is the standard requirement at most research conferences
  • Architectural and engineering drawings — large enough for a full floor plan at a readable scale
  • Retail and event posters — window displays, cinema foyers, trade stands
  • Wall planners and charts — year planners, org charts, process maps
  • Fine art prints — the largest size most consumer wide-format printers handle in one pass

Designing an A0 Poster

  • Set the document at full size — 841 × 1189 mm, not a scaled-down A3 you enlarge later
  • 150 DPI is usually enough — an A0 poster is read from a metre or more away, and 4967 × 7022 px is far easier to handle than a 139-megapixel file
  • Add 3 mm bleed on every edge, and keep text at least 10 mm inside the trim
  • Minimum body text of 24 pt — anything smaller is unreadable at poster viewing distance
  • Convert to CMYK before sending to print, and embed or outline your fonts

A0 vs US Poster Sizes

North America has no exact A0 equivalent. The nearest common formats are the 36 × 48-inch architectural poster (91.4 × 121.9 cm), which is a little wider and taller, and the 27 × 40-inch cinema one-sheet (68.6 × 101.6 cm), which is noticeably smaller. If a US printer asks for "Arch E" that is 36 × 48 inches, not A0. Full figures are on the US paper sizes page.

Larger Than A0

ISO 216 also defines 2A0 (118.9 × 168.2 cm) and 4A0 (168.2 × 237.8 cm) for oversized technical drawings. They follow the same doubling rule in reverse: 2A0 is two A0 sheets, 4A0 is four.

Related References

A Paper Sizes Chart

A0 to A10 in cm, mm and inches

Poster Sizes

Standard poster dimensions in pixels

B-Series Paper Sizes

B0 to B10 dimensions

A4 vs Letter vs Legal

Paper sizes compared side by side

DPI Calculator

Work out pixels for any print size

Pixels to cm Converter

Convert dimensions to centimetres