Pixels to inches & cm converter
Convert pixels to inches, centimetres or millimetres — and back — for any print resolution. Runs in your browser, nothing is sent anywhere.
A4, Letter and photo sizes in pixels
| Format | mm | inch | 72 dpi | 150 dpi | 300 dpi |
|---|---|---|---|---|---|
| A3 | 297 × 420 | 11.69 × 16.54 | 842 × 1191 | 1754 × 2480 | 3508 × 4961 |
| A4 | 210 × 297 | 8.27 × 11.69 | 595 × 842 | 1240 × 1754 | 2480 × 3508 |
| A5 | 148 × 210 | 5.83 × 8.27 | 420 × 595 | 874 × 1240 | 1748 × 2480 |
| A6 | 105 × 148 | 4.13 × 5.83 | 298 × 420 | 620 × 874 | 1240 × 1748 |
| US Letter | 215.9 × 279.4 | 8.50 × 11.00 | 612 × 792 | 1275 × 1650 | 2550 × 3300 |
| 10 × 15 cm | 100 × 150 | 3.94 × 5.91 | 283 × 425 | 591 × 886 | 1181 × 1772 |
| 13 × 18 cm | 130 × 180 | 5.12 × 7.09 | 369 × 510 | 768 × 1063 | 1535 × 2126 |
Values rounded to whole pixels. 300 dpi is the usual target for photo prints and offset printing; 150 dpi is fine for posters viewed from a distance.
How pixels become inches and centimetres
A pixel has no fixed physical size. The same 1920-pixel-wide image is 26.7 inches on a 72-dpi screen, 20 inches at 96 dpi and just 6.4 inches (16.3 cm) when printed at 300 dpi. That is why every conversion between pixels and a real-world length needs a third number: the resolution, expressed as dots per inch (DPI) for printers or pixels per inch (PPI) for screens. The formula is simple — inches = pixels ÷ DPI, and centimetres = inches × 2.54.
The converter above does exactly that in both directions. Enter a pixel size and a resolution to get inches, centimetres and millimetres; or start from a physical size in cm, mm or inches to find out how many pixels you need. The formula line under the result shows the calculation so you can check it or reuse it in a spreadsheet.
Which DPI should you use?
- 300 dpi — photo prints, brochures, magazines, anything held in the hand. This is the standard most print shops ask for.
- 150 dpi — posters, banners and other large prints that are viewed from a metre or more away. Half the resolution, a quarter of the pixels.
- 96 dpi — the reference resolution used by Windows and CSS (1 CSS inch = 96 px). Useful when a layout tool asks for a screen size in pixels.
- 72 dpi — the classic Macintosh screen value, still the default in many image editors. It has no meaning for modern displays but is often what a “web size” export uses.
For screens, DPI is mostly irrelevant: a browser shows a 1920 × 1080 image at 1920 × 1080 device pixels regardless of the DPI stored in the file. The number only matters when the image meets paper.
Pixels to inches for printing a photo
To check whether a photo is big enough for a print, divide its pixel dimensions by 300. A 4000 × 3000 image gives 13.3 × 10 inches (33.9 × 25.4 cm) at full quality — comfortably enough for a 12 × 8 print. A 1200 × 900 photo from a chat app gives only 4 × 3 inches at 300 dpi; printed at 8 × 6 it drops to 150 dpi and will look soft up close. Use the reverse mode to see how many pixels a target print size needs before you order.
Does changing the DPI change the image?
No. DPI is a label stored in the file that tells a printer how densely to place the pixels. Changing it from 72 to 300 in an editor without resampling leaves every pixel exactly where it was — the image simply prints smaller. To gain real detail you would need more pixels, which resizing cannot invent. If you need a smaller file for the web, use the compressor instead of lowering DPI; if you need a specific pixel size, use the resizer.
Privacy by design
All processing happens inside your browser. Your files never reach a server — there is nothing to store, transmit or share.
Learn more in our privacy policyFrequently asked questions
It depends on the resolution: 72 px at 72 dpi, 96 px at 96 dpi, 300 px at 300 dpi. One inch is always 2.54 cm, but the number of pixels in it is set by the DPI you choose.
Divide the pixels by the DPI to get inches, then multiply by 2.54. Example: 1200 px ÷ 300 dpi = 4 in × 2.54 = 10.16 cm.
PPI (pixels per inch) describes pixel density in an image or on a screen; DPI (dots per inch) describes the ink dots a printer places. In everyday use — and in this converter — both mean the same thing: how many pixels fit into one inch.
2480 × 3508 pixels. A4 is 210 × 297 mm, which is 8.27 × 11.69 inches; multiplied by 300 that gives 2480 × 3508. At 150 dpi it is 1240 × 1754, at 72 dpi 595 × 842.
No. The calculation runs entirely in your browser with JavaScript; there is no server involved and nothing is stored.