Resize Image in Pixels, CM or Inches

Set exact width and height in pixels, centimetres, millimetres or inches, with DPI stored in the file.

Your files never leave your device. Processing happens in your browser.

How to use the Resize Dimensions

Choose your image.
Pick a unit (px, cm, mm or inches) and enter the width and height.
Set the DPI; physical sizes are converted to pixels at this DPI.
Choose JPG, PNG or WebP and quality, then click Resize.
Download the resized image.

Pixels, centimetres and DPI explained

Screens think in pixels, but forms and printers often talk in centimetres or inches. DPI (dots per inch) connects the two: at 300 DPI, one inch equals 300 pixels. So a 3.5 × 4.5 cm passport photo at 300 DPI is 413 × 531 pixels. This tool does that maths for you and also writes the DPI into the file, so printers and form validators read the intended physical size.

Common sizes

Size	At 300 DPI
3.5 × 4.5 cm (Indian passport)	413 × 531 px
2 × 2 in (US passport, Indian visa)	600 × 600 px
5 × 7 in print	1500 × 2100 px
A4 page	2480 × 3508 px

Keep aspect ratio, or stretch?

With the lock on, changing the width updates the height to match the original shape, so nothing looks squashed. Turn it off only when a form insists on exact dimensions that differ from your photo’s shape; in that case it is usually better to crop first with the image cropper so the face isn’t distorted.

Which format should I choose?

JPG: photos and most forms. Adjust quality to balance size and detail.
PNG: graphics, logos and screenshots with sharp edges or transparency.
WebP: websites; smaller than JPG at the same quality, but not accepted by every form.

Need a file size limit too?

After resizing, run the file through the KB resizer if the form also caps the size. For exam applications, the exam resizer sets pixels, KB and DPI in one go. Everything runs in your browser, so your photos stay private.

Quick answers

How many pixels is a 2 × 2 inch photo? 600 × 600 at 300 DPI. How many pixels is A4 at 150 DPI? About 1240 × 1754. Which DPI should I choose for a form that only mentions centimetres? Use the DPI in the notification; if none is given, 300 DPI is the safe print-quality default.

Frequently asked questions

How many pixels is 3.5 × 4.5 cm?

At 300 DPI it is 413 × 531 pixels. At 200 DPI it is 276 × 354 pixels. The tool shows the pixel size for any DPI.

Does changing DPI change image quality?

DPI alone doesn't change pixels; it tells printers how big to print. Here, DPI is also used to convert cm or inches into pixels.

Can I enlarge a small image?

Yes, up to 12,000 pixels per side, but enlarging can't add detail, so the result may look soft.

Is the DPI saved in the file?

Yes, for JPG and PNG. WebP has no standard DPI field.

Will my photo be stretched?

Not while 'Keep aspect ratio' is ticked. Untick it only if you need exact dimensions of a different shape.