When people say “passport-size photo,” they often mean a workflow, not one universal specification. This guide treats the requirement as an application-specific job.
Keep the units straight
Millimetres and inches describe physical output; pixels describe digital dimensions; DPI connects pixels to physical size during printing. If an authority already states the required pixel dimensions, use them directly. If you are building a print file from millimetres, the basic relationship is pixels = millimetres × DPI ÷ 25.4.
Where calculations stop being enough
A mathematically correct file can still fail because the face is the wrong size inside the frame, the background is unsuitable, the compression introduces visible artefacts, or the application expects a different file type. Finish every conversion with a visual and application-specific check.
For families
Check the person, destination and file name together before each upload. Similar-looking portraits make mix-ups easy when a family is preparing several forms at once.
Why a checklist helps
People tend to remember the size and forget the background, file limit or editing rule. A short preflight checklist prevents that imbalance and keeps the final export tied to the actual application.
What to remember from this page
For recurring applications, keep a tiny photo record: date taken, destination, dimensions and final format. It is more reliable than remembering a size from a previous application.
How to Convert 45×35 mm to Pixels
Use the Studio for production and the issuing authority for the rule. That separation keeps the workflow practical and honest.