Resize an image in centimetres
To resize an image in centimetres, choose cm, type the width and height, and pick the DPI (300 is right for print). The tool converts to pixels for you: pixels = centimetres ÷ 2.54 × DPI, so 3.5 × 4.5 cm at 300 DPI is 413 × 531 pixels.
Free · no signup · your files never leave your device
How it works
- Drop your picture into the box above, or paste it with Ctrl+V.
- Choose how to set the size and type the new numbers. The other side follows so the picture is not stretched.
- Check the result, then download it.
Common centimetre sizes in pixels
- 3.5 × 4.5 cm (passport): 413 × 531 px at 300 DPI, 207 × 266 px at 150 DPI, 99 × 128 px at 72 DPI
- 5 × 7 cm: 591 × 827 px at 300 DPI, 295 × 413 px at 150 DPI, 142 × 198 px at 72 DPI
- 10 × 15 cm (4×6 print): 1181 × 1772 px at 300 DPI, 591 × 886 px at 150 DPI, 283 × 425 px at 72 DPI
- 13 × 18 cm (5×7 print): 1535 × 2126 px at 300 DPI, 768 × 1063 px at 150 DPI, 369 × 510 px at 72 DPI
- A5 14.8 × 21 cm: 1748 × 2480 px at 300 DPI, 874 × 1240 px at 150 DPI, 420 × 595 px at 72 DPI
- A4 21 × 29.7 cm: 2480 × 3508 px at 300 DPI, 1240 × 1754 px at 150 DPI, 595 × 842 px at 72 DPI
Why DPI matters here
Centimetres are a physical size, pixels are dots. DPI says how many dots fit in an inch. A form that only gives centimetres still needs pixels on screen; 300 DPI is the usual choice for anything that will be printed, and 72 to 96 for screens.
Printing at the right size
Print at 100% scale, not 'fit to page', or the printed size will change. If a print shop asks for a size in cm, give them a file made at 300 DPI.
Questions people ask
How do I change the size of a photo to 3.5 × 4.5 cm?
Choose cm, type 3.5 and 4.5, keep 300 DPI, and download. The result is 413 × 531 pixels.
How do I convert centimetres to pixels?
Divide the centimetres by 2.54 and multiply by the DPI. For 10 cm at 300 DPI that is about 1181 pixels.
Which DPI should I use?
300 for print, 150 for casual prints, 72 or 96 for screens.
Is it free?
Yes. There is no signup, no watermark and no limit on how many pictures you resize.
Is my picture uploaded?
No. The picture is resized inside your browser, so it never leaves your device.