The 35x45 mm photo: the closest thing to a world standard

If you have applied for a visa anywhere in Europe, you have used a 35 mm by 45 mm photo. It derives from the International Civil Aviation Organization's machine-readable travel document specification, which most countries adopted for passports and visas.

What the general standard says

The photo is 35 mm wide and 45 mm tall, a 7:9 ratio. The head should occupy roughly 70 to 80 percent of the frame height, which works out to about 32 to 36 mm from chin to crown. The expression is neutral, the background is plain and light, and the head is square to the camera.

That ratio is worth remembering, because 420 by 540 pixels, 700 by 900 pixels and 350 by 450 pixels are all the same 7:9 shape. IRCC's digital minimum of 420 by 540 is simply a 35 by 45 mm photo expressed in pixels.

Where countries deviate

The size is consistent but the head height is not, and this catches people who reuse a photo across applications.

• United Kingdom: 29-34 mm, noticeably smaller than the general standard, on a light grey or cream background.
• Ireland: 31.5-36 mm, on light grey or light blue, never white.
• Germany: 32-36 mm, on plain light grey, applied strictly against a national template.
• Japan: 34 mm plus or minus 2 mm, with an explicit 2-6 mm gap required above the head.
• Singapore: a wide 25-35 mm range, on plain white.
• Australia: 32-36 mm, glasses must be removed.

Formats that are not 35x45

Plenty of countries never adopted it. Canada uses 50 by 70 mm, the United States a 2 inch square, China 33 by 48 mm, Malaysia 35 by 50 mm, Bangladesh 45 by 55 mm, Finland 36 by 47 mm, and Spain an unusual 26 by 32 mm. Assuming 35 by 45 is universal is a reliable way to have a photo returned.

One photo, many exports

The practical approach is to take a single high-resolution, well-lit photo with plenty of space around your head, then export it separately for each country using that country's head height rule. Because the source photo has room to breathe, each export can scale the head correctly without running out of image.