Poster Sizes Chart: US and International

Posters come in two sets of standard sizes: US sizes in inches (11 × 17, 18 × 24, 24 × 36) and the international A sizes (A3, A2, A1, A0) used almost everywhere else. They’re close but not the same, so a poster designed for one may need cropping for the other.

US poster sizes

Size (in)	Size (cm)	Common use
11 × 17	27.9 × 43.2	Flyers, notice boards (Tabloid / Ledger paper)
12 × 18	30.5 × 45.7	Small art prints, event posters
16 × 20	40.6 × 50.8	Photo enlargements, art prints
18 × 24	45.7 × 61.0	Medium posters, presentations, signs
24 × 36	61.0 × 91.4	Standard full-size posters
27 × 40	68.6 × 101.6	Movie posters (one-sheet)
36 × 48	91.4 × 121.9	Trade shows, research posters

International (A) poster sizes

Size	mm	Inches	Common use
A4	210 × 297	8.3 × 11.7	Notices, small prints
A3	297 × 420	11.7 × 16.5	Small posters, flyers
A2	420 × 594	16.5 × 23.4	Medium posters, art prints
A1	594 × 841	23.4 × 33.1	Large posters, presentations
A0	841 × 1189	33.1 × 46.8	Conference and research posters

Each A size is exactly half the one before it, so an A1 poster folds into two A2s. The paper sizes chart explains the system.

Pixels you need for a sharp poster

Multiply the size in inches by the resolution. 150 PPI is enough for posters viewed from a few feet away; 300 PPI is photo quality for close viewing.

Poster	At 150 PPI	At 300 PPI
11 × 17 in	1650 × 2550 px	3300 × 5100 px
18 × 24 in	2700 × 3600 px	5400 × 7200 px
24 × 36 in	3600 × 5400 px	7200 × 10800 px
27 × 40 in	4050 × 6000 px	8100 × 12000 px
A3	1754 × 2480 px	3508 × 4961 px
A2	2480 × 3508 px	4961 × 7016 px
A1	3508 × 4967 px	7016 × 9933 px

A phone photo of 12 megapixels (about 3000 × 4000 pixels) prints well up to about 18 × 24 inches. The pixels to inches converter works this out for any image.

Matching shapes

Posters have different shapes (aspect ratios), and an image only fills a poster of the same shape without cropping:

• 2:3, like a camera photo: 4 × 6, 12 × 18, 24 × 36.
• 3:4, like a phone photo: 18 × 24, 36 × 48.
• 4:5: 8 × 10, 16 × 20.
• 1:√2 (about 1:1.41), all the A sizes: A3, A2, A1, A0.
• 27 × 40 is its own shape (about 2:3).

How far away can a poster be read?

A common sign-making rule: every inch of letter height can be read from about 10 feet away, and is best read from about 4 feet. So a title in 2 inch letters on an 18 × 24 poster carries across a room of 20 feet, while body text needs to be at least ½ inch tall to read from 5 feet. For a conference poster, make the title at least 2 inches tall and body text about 24 to 36 points or more.

Choosing a size for a wall

Over a sofa or bed, art usually looks best at about two-thirds of the furniture’s width. For a 7-foot (84 inch) sofa, that’s about 56 inches of art: one 36 × 48 poster hung sideways, or two framed 24 × 36 posters side by side with a few inches between them. Hang the center of the poster at about 57 to 60 inches from the floor, the typical eye level used by galleries.