Poster Sizes
Standard poster sizes (11×17 to 27×40 in, A3 to A0, B1, B2, 50×70 cm) in inches, cm and mm, with aspect ratios and the pixels needed at any DPI.
Frames are sold for these exact sizes; a print with a different ratio needs cropping or a mat.
150 DPI is usually enough for posters seen from a metre or more; use 300 DPI for small posters viewed up close.
| Size | inches | cm | ratio | pixels |
|---|---|---|---|---|
| 11 × 17 in | 11 × 17 | 27.9 × 43.2 | 11:17 | 1650 × 2550 |
| 12 × 18 in | 12 × 18 | 30.5 × 45.7 | 2:3 | 1800 × 2700 |
| 16 × 20 in | 16 × 20 | 40.6 × 50.8 | 4:5 | 2400 × 3000 |
| 18 × 24 in | 18 × 24 | 45.7 × 61 | 3:4 | 2700 × 3600 |
| 20 × 30 in | 20 × 30 | 50.8 × 76.2 | 2:3 | 3000 × 4500 |
| 24 × 36 in | 24 × 36 | 61 × 91.4 | 2:3 | 3600 × 5400 |
| 27 × 40 in | 27 × 40 | 68.6 × 101.6 | 27:40 | 4050 × 6000 |
| A3 | 11.69 × 16.54 | 29.7 × 42 | 1:√2 (1:1.414) | 1754 × 2480 |
| A2 | 16.54 × 23.39 | 42 × 59.4 | 1:√2 (1:1.414) | 2480 × 3508 |
| A1 | 23.39 × 33.11 | 59.4 × 84.1 | 1:√2 (1:1.414) | 3508 × 4967 |
| A0 | 33.11 × 46.81 | 84.1 × 118.9 | 1:√2 (1:1.414) | 4967 × 7022 |
| B2 | 19.69 × 27.83 | 50 × 70.7 | 1:√2 (1:1.414) | 2953 × 4175 |
| B1 | 27.83 × 39.37 | 70.7 × 100 | 1:√2 (1:1.414) | 4175 × 5906 |
| 50 × 70 cm | 19.69 × 27.56 | 50 × 70 | 5:7 | 2953 × 4134 |
| 70 × 100 cm | 27.56 × 39.37 | 70 × 100 | 7:10 | 4134 × 5906 |
Posters come in a handful of standard sizes so that frames, tubes and printers all match: 18 × 24 and 24 × 36 inches in the US, A2, A1 and 50 × 70 cm in Europe and Asia, and the 27 × 40 inch one-sheet for films. This tool lists each size in inches, centimetres and millimetres, shows its aspect ratio, and tells you how many pixels your artwork needs for a sharp print.
How to use this tool
- Pick a poster size.
- Choose portrait or landscape.
- Pick the print resolution — 150 DPI suits most wall posters.
- Create or export your artwork at the pixel size shown, or check that your photo is large enough.
Formula
pixels = round(inches × DPI) = round(mm ÷ 25.4 × DPI) · aspect ratio = width ÷ gcd : height ÷ gcd
ISO A and B posters keep the 1:√2 shape, so artwork scales between A3, A2 and A1 without cropping. US sizes have different ratios (2:3, 3:4, 4:5), so moving between them requires cropping.
Example
A 24 × 36 inch poster at 300 DPI needs 24 × 300 = 7200 by 36 × 300 = 10,800 pixels (77.8 megapixels); at 150 DPI it is 3600 × 5400. Its ratio is 2:3, the same as a 35 mm photo, so a full-frame camera image fits without cropping.
Frequently asked questions
Can I print a phone photo as a big poster?
A 12-megapixel photo (4000 × 3000) gives about 26.7 × 20 inches at 150 DPI, so an 18 × 24 poster prints well and 24 × 36 is acceptable from a distance.
What is the standard movie poster size?
The US one-sheet is 27 × 40 inches today; older posters were 27 × 41.
Is A1 bigger than 24 × 36?
No. A1 is 594 × 841 mm (23.4 × 33.1 in), a little smaller than 24 × 36 in (610 × 914 mm).
Last updated:
Page address with these inputs: https://kakao.mobile/tools/poster-size-tool/
Cite or embed this tool
kakaoCalc. (2026, November 8). Poster Sizes. https://kakao.mobile/tools/poster-size-tool/
“Poster Sizes.” kakaoCalc, 8 Nov. 2026, kakao.mobile/tools/poster-size-tool/.
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