Head height is the requirement people miss
Almost everyone searching for a passport photo size finds the photo’s outer dimensions — 35 × 45 mm in the UK, 2 × 2 inches in the US — and stops there. Those numbers are the easy part, and getting them right on their own does not produce an acceptable photo.
The requirement that decides acceptance is how large your head is within that frame, measured from the bottom of your chin to the crown of your head. The UK permits 29 to 34 mm inside a 45 mm photo, which is a window of five millimetres. Outside it, the application is refused — too small and too large both fail.
You cannot judge that by eye, and cropping to the right outer size in an image editor tells you nothing about it. That is the whole reason a tool is useful here: everything else is a rectangle, but this is a proportion you have to compute.
What a tool can and cannot do for you
Geometry is arithmetic, and arithmetic can be verified. The numbers behind these pages are checked by an automated test on every change — that the crop comes out at the right aspect ratio on portrait and landscape sources alike, that the head lands in the middle of the permitted range rather than at its edge, that the printed sheet reproduces photos at exactly the right physical size.
What no tool can assess is the photograph. Shadows on the face or behind the head, a background that is not plain, glare on glasses, a hint of a smile, eyes half-closed — these account for most rejections and none of them can be measured reliably from a single image. Each country page lists the authority’s own stated rejection reasons, because knowing them before you take the photo is worth more than any amount of processing afterwards.
Taking the photo
Stand about a metre in front of a plain, light, unpatterned wall, and stand far enough from it that your shadow does not fall on it. Face a window so the light comes from in front of you and is even across your face. Have somebody else take the picture from roughly your eye level, about a metre and a half away — a selfie at arm’s length exaggerates the nose and narrows the ears, which is a genuine and common cause of rejection.
Leave space around your head. A photo cropped tightly to your face cannot be re-cropped to the required proportions, and there is no way to add back what was never in the frame. If in doubt, stand further away.
Not affiliated with any authority
This site has no connection to any government or passport office. Every specification here links to the authority that publishes it, and you should read that page before submitting. We cannot guarantee that any photo will be accepted.