Resize an image in centimetres or inches

Printers and forms talk in centimetres and inches, pictures talk in pixels. Enter the physical size and a DPI and this does the sum and saves the file correctly.

Drop images here

Your files stay on your device. You can also paste or drag files in.

How to resize an image in centimetres or inches

  1. Add your picture.
  2. Choose the unit and enter the width and height you need.
  3. Set the DPI. 300 is the usual choice for printing, 72 to 96 for screens.
  4. Press Resize images. The file is saved at that DPI.

Good to know

  • The sum is pixels = size in inches times DPI. So 10 cm at 300 DPI is 1181 pixels, and an A4 sheet of 21 by 29.7 cm is 2480 by 3508 pixels.
  • DPI is a tag that tells a printer how large to make the picture. The pixels are what matter. The same file at 300 DPI prints smaller than at 150 DPI.
  • With the proportions unlocked, the picture is stretched to the exact size you typed. Lock them to keep it undistorted.

Questions

How many pixels is 10 cm?

At 300 DPI, 10 cm is 1181 pixels. At 96 DPI it is 378 pixels. The result depends entirely on the DPI you choose.

Does the DPI get saved?

Yes, for JPG and PNG files. WEBP has no DPI field, so the pixels are right but the tag cannot be stored.

Why does my printer ignore the size?

Many apps scale pictures to fit the page and disregard the DPI tag. The pixel count is the part you control.

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