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Pixels to CM Converter

Convert pixels to cm, inches and mm at any DPI value

Privacy: your files never leave your device. All processing happens locally in your browser.

How to use

  1. 1.Type a number and choose its unit - pixels, centimetres, inches or millimetres.
  2. 2.Set the DPI: 96 for screens, 300 for print, or type any custom value.
  3. 3.Read the converted pixels, cm, inches and mm instantly in the results table.

About Pixels to CM Converter

A pixel is just a single point in a digital image, and on its own it has no physical size. Ask "how many centimetres is 100 pixels?" and the only honest answer is "it depends" - specifically, it depends on the resolution, measured in DPI (dots per inch) or the closely related PPI (pixels per inch). This pixels to cm converter turns that abstract relationship into a concrete number: type a value in pixels, centimetres, inches or millimetres, set a DPI, and it instantly shows the other three units.

The maths is simple once you route everything through inches. To go from pixels to a physical length, divide by the DPI: inches = pixels / DPI. From there, centimetres = inches x 2.54 and millimetres = inches x 25.4, because one inch is defined as exactly 2.54 cm (the 1959 international inch). To go the other way - cm, mm or inches back to pixels - convert the length to inches first, then multiply by the DPI. So 96 pixels at 96 DPI is exactly 1 inch, 2.54 cm and 25.4 mm, while 1 cm at 96 DPI works out to 96 / 2.54 = about 37.8 pixels.

Choosing the right DPI is the part people get wrong. Web browsers and most screens use 96 DPI, because the CSS specification defines the reference pixel as 1/96 of an inch - that is why 96 is the default here. Printing is different: high-quality print work is usually done at 300 DPI, so an image that looks fine on screen can be far too small on paper unless you plan for it. Some older images and web graphics are tagged at 72 DPI, a legacy value from early desktop publishing. The tool offers 72, 96, 150 and 300 as one-tap presets, and you can type any custom value in between.

These conversions come up constantly in real work. Passport and ID photos are specified in physical sizes - a common 3.5 cm wide photo needs about 413 pixels at 300 DPI to print sharply. Anyone preparing artwork for print, from flyers to posters, has to translate a pixel canvas into real-world centimetres and millimetres. Web and UI designers do the reverse, sizing screen elements that a client has described in centimetres. Photographers and print shops use it to check whether an image has enough pixels to fill a given paper size at an acceptable density.

One point of vocabulary: DPI and PPI are technically different - DPI describes ink dots a printer lays down, while PPI describes pixels on a screen - but for the purpose of converting pixels to a physical length they are used interchangeably, and this tool treats them as the same number. Everything runs locally in your browser, with no upload and no waiting, so you get an instant, private answer every time.

Frequently asked questions

How do I convert px to cm?
Divide the pixels by the DPI to get inches, then multiply by 2.54. For example, 96 px at 96 DPI is 1 inch, which is 2.54 cm. At 300 DPI, 96 px is only 96/300 inch, about 0.81 cm.
What DPI should I use?
Use 96 DPI for screens and the web (the CSS reference pixel), and 300 DPI for high-quality printing. Some legacy images are tagged at 72 DPI. When in doubt, match the DPI your printer or export setting expects.
How many pixels are in 1 cm?
At 96 DPI, 1 cm = 1/2.54 x 96, about 37.8 pixels. At 300 DPI it is 1/2.54 x 300, about 118.1 pixels. The pixel count scales directly with the DPI, so a higher DPI means more pixels per centimetre.
What is px to cm at 300 DPI?
At 300 DPI, 300 px = 1 inch = 2.54 cm. In general, cm = px / 300 x 2.54. So a 3.5 cm ID-photo width needs 3.5 / 2.54 x 300, about 413 pixels.
Is DPI the same as PPI?
Not exactly - DPI (dots per inch) is a printing term and PPI (pixels per inch) is a screen term - but for converting pixels to a physical length they are numerically interchangeable, and this converter treats them as the same value.

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