A Paper Sizes Chart: A0, A1, A2, A3, A4, A5

The full A-series paper sizes chart under ISO 216, from A0 at 84.1 × 118.9 cm (841 × 1189 mm) down to A10. Every size in centimetres, millimetres, inches, and pixels at 72, 150, and 300 DPI. Used as the standard paper size everywhere except North America.

A Series Paper Sizes Chart — cm, mm & Inches

Size	Millimeters (mm)	Centimeters (cm)	Inches (in)	Common Use
A0	`841 × 1189 mm`	84.1 × 118.9 cm	33.1 × 46.8 in	Technical drawings, posters
A1	`594 × 841 mm`	59.4 × 84.1 cm	23.4 × 33.1 in	Flip charts, large posters
A2	`420 × 594 mm`	42.0 × 59.4 cm	16.5 × 23.4 in	Medium posters, diagrams
A3	`297 × 420 mm`	29.7 × 42.0 cm	11.7 × 16.5 in	Tabloid, large prints
A4	`210 × 297 mm`	21.0 × 29.7 cm	8.3 × 11.7 in	Standard documents, letters
A5	`148 × 210 mm`	14.8 × 21.0 cm	5.8 × 8.3 in	Notepads, booklets
A6	`105 × 148 mm`	10.5 × 14.8 cm	4.1 × 5.8 in	Postcards, flyers
A7	`74 × 105 mm`	7.4 × 10.5 cm	2.9 × 4.1 in	Small notepads
A8	`52 × 74 mm`	5.2 × 7.4 cm	2.0 × 2.9 in	Playing cards
A9	`37 × 52 mm`	3.7 × 5.2 cm	1.5 × 2.0 in	Stamps, labels
A10	`26 × 37 mm`	2.6 × 3.7 cm	1.0 × 1.5 in	Tiny labels

A Paper Sizes in Pixels (72, 150 & 300 DPI)

Size	72 DPI (Web/Screen)	150 DPI (Draft Print)	300 DPI (Print Standard)
A0	`2384 × 3370 px`	`4967 × 7022 px`	`9933 × 14043 px`
A1	`1684 × 2384 px`	`3508 × 4967 px`	`7016 × 9933 px`
A2	`1191 × 1684 px`	`2480 × 3508 px`	`4961 × 7016 px`
A3	`842 × 1191 px`	`1754 × 2480 px`	`3508 × 4961 px`
A4	`595 × 842 px`	`1240 × 1754 px`	`2480 × 3508 px`
A5	`420 × 595 px`	`874 × 1240 px`	`1748 × 2480 px`
A6	`298 × 420 px`	`620 × 874 px`	`1240 × 1748 px`
A7	`210 × 298 px`	`437 × 620 px`	`874 × 1240 px`

Understanding A-Series Paper Sizes

The √2 Ratio System

A-series paper is based on ISO 216 standard. The key principle: each size is exactly half of the previous size when folded, and all sizes have the same aspect ratio (√2:1 or 1:1.414).

How It Works

A0: Base size with area of exactly 1 m² (841 × 1189 mm)
A1: A0 cut in half = 594 × 841 mm
A2: A1 cut in half = 420 × 594 mm
A3: A2 cut in half = 297 × 420 mm
A4: A3 cut in half = 210 × 297 mm (most common)
A5: A4 cut in half = 148 × 210 mm

Why √2 Aspect Ratio?

When you fold a sheet in half along its longer side, it retains the same proportions. This makes scaling and printing incredibly efficient — no waste when converting between sizes.

A4 — The Global Standard

A4 (210 × 297 mm) is the most common paper size worldwide, equivalent to "Letter" size in the US (though slightly narrower and taller).

Used in 90%+ of countries for standard documents
At 300 DPI: 2480 × 3508 pixels
At 150 DPI: 1240 × 1754 pixels (draft quality)
PDF page size: 595 × 842 points (at 72 PPI)

Common Use Cases

A0/A1: Architectural drawings, engineering plans, large format posters
A2/A3: Posters, presentations, newspapers (A3 is tabloid size)
A4: Office documents, letters, magazines, brochures (standard printer size)
A5: Notepads, greeting cards, booklets (half of A4)
A6: Postcards, flyers, invitations

Designing for Print

Use 300 DPI for professional print quality
Add bleed: Extend design 3mm beyond edge for trimming
Safe zone: Keep text/logos 5mm inside margins
CMYK color: Use CMYK, not RGB, for accurate print colors
Embed fonts: Convert text to outlines or embed fonts in PDF

A-Series vs. US Paper

North America uses different standards:

Letter (8.5 × 11"): Slightly wider, shorter than A4
Legal (8.5 × 14"): Taller than Letter
Tabloid (11 × 17"): Similar to A3 but different aspect ratio

Common A Paper Size Questions

How big is A0 in cm?

A0 is 84.1 × 118.9 cm — that is 841 × 1189 mm, or 33.1 × 46.8 inches. It is the largest sheet in the standard A series and covers almost exactly one square metre (0.999 m²), which is how the whole system is defined. Every smaller size is A0 halved again and again. For the full breakdown, see the dedicated A0 paper size page.

What is the difference between A0 and A1?

A1 is exactly half of A0. Fold an A0 sheet across its long side and you get A1 at 59.4 × 84.1 cm — same 1:√2 proportions, half the area. The same relationship holds all the way down: A1 halves into A2, A2 into A3, and so on.

A0 to A5 at a glance

A0: 84.1 × 118.9 cm — 841 × 1189 mm — 33.1 × 46.8 in
A1: 59.4 × 84.1 cm — 594 × 841 mm — 23.4 × 33.1 in
A2: 42.0 × 59.4 cm — 420 × 594 mm — 16.5 × 23.4 in
A3: 29.7 × 42.0 cm — 297 × 420 mm — 11.7 × 16.5 in
A4: 21.0 × 29.7 cm — 210 × 297 mm — 8.3 × 11.7 in
A5: 14.8 × 21.0 cm — 148 × 210 mm — 5.8 × 8.3 in

Which A size is a poster?

Most shop-bought and printed posters land between A2 and A0. A2 (42 × 59.4 cm) suits a bedroom wall or a shop window; A1 (59.4 × 84.1 cm) is the usual size for cinema and event posters in Europe; A0 (84.1 × 118.9 cm) is used for exhibition boards, academic posters, and large-format advertising. Compare these with US poster formats on the poster print sizes page.

How many pixels do I need for each A size?

Multiply the size in inches by your target DPI. At the 300 DPI print standard that gives 2480 × 3508 px for A4, 3508 × 4961 px for A3, and 9933 × 14043 px for A0. At 150 DPI — acceptable for large prints viewed from a distance — halve those figures. The pixel table above lists every size, and the DPI calculator works out any combination you need.

Why is A4 not the same as US Letter?

A4 (21.0 × 29.7 cm) is 6 mm narrower and 18 mm taller than US Letter (21.6 × 27.9 cm). The two are close enough that documents usually print on either, but a full-bleed design made for one will be cropped or margined on the other. See the side-by-side paper size comparison or the full US paper sizes reference.

What about B and C series paper?

ISO 216 also defines a B series, which sits between consecutive A sizes and is used for posters, books, and envelopes, and a C series sized for envelopes that hold A-series sheets — a C4 envelope takes an unfolded A4 page. Full figures are on the B-series paper sizes page.