Passport photo size checker

Every measurement assumes the photo is scaled so the suggested crop fills the exact print size, so head height in millimetres is read off that crop. There is no face detection here: you mark the crown and chin, and the tool measures the gap. The background figure is the average brightness of the border pixels, a proxy for a plain light backdrop rather than a real background rule. The rule numbers come from the issuing offices' published guidance, but the issuing office decides acceptance, not this page.