px to cm Converter

A pixel is a counting unit, not a length. An image 1,000 pixels wide is just a grid with 1,000 columns; how wide it appears depends on how many of those columns are packed into each inch of screen or paper. That density is DPI, dots per inch, or PPI when people mean screen pixels. Once it is fixed, converting is straightforward: divide the pixels by the DPI to get inches, then multiply by 2.54, the exact number of centimeters in an inch.

The table below runs that conversion for common print widths at 300 DPI. It reads both ways: find a width in centimeters and see how many pixels it needs, or find a pixel count and see the print width it gives.

A common source of confusion is the DPI value stored inside image files. Many photos say 72 DPI in their properties, others 300, and the number is often just a default written by the camera or editor. It changes nothing on screen. It only tells print and layout programs what physical size to use, which is why the converter asks you for the DPI instead of guessing it.

The default of 96 comes from the web. The W3C's CSS Values and Units specification fixes 1 inch at exactly 96 CSS pixels, and 1 centimeter therefore at 96 ÷ 2.54, about 37.8 pixels. When a web designer says a box is 378 pixels wide, it is 10 cm in CSS terms, even though the physical size on a phone or a 4K monitor will differ, because devices scale CSS pixels to their own screens.

Print is different. A printer lays down real dots, and around 300 per inch is the usual target for photos and documents viewed up close. At that density one centimeter needs about 118 pixels, more than three times as many as at 96. If you are preparing an image for print, always convert at the printer's DPI, not the screen default, or the picture will come out far smaller than you expect.

Forms that ask for a photo in centimeters and pixels at the same time usually have a DPI in mind, even if they do not state it. Divide their pixel count by their centimeters and multiply by 2.54: a result near 300 tells you to convert at 300 DPI.

Pixels are whole numbers, but centimeters rarely are. The converter shows two decimal places by default, which is a tenth of a millimeter and finer than any printer or ruler needs. Raise Decimal places when you chain conversions, so rounding errors do not add up, and lower it for labels and quick checks.

The Keep aspect ratio option under Advanced settings helps with a related job: if you know one side and the shape, such as a 16:9 slide, it shows the other side as well, so you can convert both dimensions of a frame at once.

The same converter goes the other way, from centimeters to pixels, by swapping From and To. It also handles millimeters, inches and points, and file sizes from bytes to terabytes, with a choice of 1,000- or 1,024-byte kilobytes. The main Pixel Converter page has every unit with no preset.

If you need an image file at a size in centimeters rather than a number, the resize in centimeters page does the conversion and the resize in one step, and stores the DPI in the file so print programs place it correctly. For a fixed pixel size, Resize Image takes width and height in pixels directly.

Nothing is uploaded on this page, since you only type numbers, and there is no account or limit on how many conversions you run.