Passport and ID photo sizes explained: mm, pixels and KB

Photo requirements often mix three different measurements, and mixing them up is the most common reason an upload is rejected. Read the instructions carefully to see which ones apply to you.

Physical size, pixels and file size

Millimetres or inches describe a printed photo. Pixels describe a digital image. Kilobytes describe the file. To convert print size to pixels, multiply inches by the resolution: 35 x 45 mm is about 1.38 x 1.77 inches, which at 300 dpi is roughly 413 x 531 pixels. A 2 x 2 inch photo at 300 dpi is 600 x 600 pixels.

Using the resizer

Choose the size in Passport/ID Image Resizer and set a maximum file size. The tool crops from the center to the correct proportions, resizes, then lowers JPEG quality until the file fits the limit. If your face is off-center in the original, crop the photo first so the head ends up in the middle.

When the size limit is very small

Fitting a low limit, such as 20 KB, forces heavy compression and visible blocks. If the form allows, use smaller pixel dimensions rather than lower quality. The tool warns when it cannot reach your target.

What the tool cannot check

It does not measure head size, check the background color, judge expression, or detect glasses or shadows. Those are the usual reasons real applications are refused. Confirm the exact rules with the issuing office and check the result against them. Always upload a JPEG made from your original photo, not a screenshot of it.

Related: all guides and all tools.