How to Resize an Image in CM for Passport Photos

Passport and visa requirements are written in centimetres — 3.5 × 4.5 cm is the standard across India, the UK, and much of Europe, while the US uses 2 × 2 inches (5.1 × 5.1 cm). But image files don't have centimetres; they have pixels. The bridge between the two is DPI.

How cm become pixels

DPI (dots per inch) states how many pixels represent one inch of physical size. The formula: pixels = cm ÷ 2.54 × DPI. At 300 DPI — the standard for print and official photos — a 3.5 × 4.5 cm photo is 413 × 531 pixels. At 96 DPI (screen resolution) the same physical size would be only 132 × 170 pixels, which looks fine on screen but prints blurry. When in doubt, use 300 DPI.

Common sizes at 300 DPI

• India / UK / EU passport photo: 3.5 × 4.5 cm → 413 × 531 px
• US passport photo: 5.1 × 5.1 cm → 602 × 602 px
• Stamp-size photo: 2 × 2.5 cm → 236 × 295 px

Step by step

1. Open the resizer and choose Print size (cm) mode.
2. Enter the width and height in cm from your requirement, and leave DPI at 300.
3. If the portal also caps the file size (most do — often 20KB or 50KB), enter that number in the optional max-size box. The tool holds the exact dimensions and adjusts only the quality to fit.
4. Drop your photo and press Resize. The photo is centre-cropped to the exact shape — so start from a picture where the face is centred with some margin around it.

Why centre-crop instead of stretch?

If a 4:3 photo is forced into a 3.5:4.5 shape by stretching, the face distorts — instantly rejectable. Cropping keeps proportions honest and simply trims the excess. The trade-off: make sure nothing essential sits at the edges of your original.

A note on privacy

Passport photos are identity documents. This resizer processes them entirely in your browser — the image never leaves your device, which is worth caring about for this particular kind of photo.