Most of the world uses one photo size and the United States uses another, which is why the first question on any application is which country you are applying to. Beyond the size itself there are two numbers that decide whether your file is usable — pixels and DPI — and they cause more confusion than the millimetres do. This guide covers where the formats come from, what to do about print density, and how to print a sheet of photos for the cost of a single one.
The three families of format
35 × 45 mm is the international default: the European Union, the United Kingdom, Australia, New Zealand, most of Asia and most of Africa. It is close to the proportions recommended by ICAO for machine-readable travel documents, which is why it spread so widely. If you are applying anywhere and do not know the format, this is the one to expect.
2 × 2 inches (50.8 × 50.8 mm) is the square American format, used for US passports and US visas, and copied by a number of countries that process a lot of American paperwork — India, Thailand, Vietnam and others accept or require it for visas. It is the only widely used square format, and cropping a 35 × 45 photo into it never works: the aspect ratio is completely different.
Then there are national exceptions. Canada uses a taller 50 × 70 mm frame that includes the shoulders. China's passport photo is 33 × 48 mm. Japan uses 35 × 45 but specifies a 4 mm margin above the head, which no other country does. Brazil, Colombia, Greece and Turkey each have their own. The catalogue on this site lists each of them with its own measurements.
Why head height matters more than photo size
Two countries can share the 35 × 45 frame and still demand different photos. The United Kingdom asks for a head of 29 to 34 mm; Germany and most of the European Union ask for 32 to 36 mm. Those ranges barely overlap, so a photo cropped for a British passport is out of specification for a German one, even though both prints are exactly the same size.
This is the reason a photo cannot simply be resized from one format to another. Changing the size of the print changes the size of the head proportionally, and the head has its own absolute requirement in millimetres. Recrop from the original instead — it takes a few seconds and it is the difference between a valid photo and a resized one.
Pixels, millimetres and DPI
DPI — dots per inch — is the bridge between the digital file and the printed photo. It answers one question: how many pixels of the file go into each inch of paper. At 300 DPI, a 35 × 45 mm photo is 413 × 531 pixels; at 600 DPI, the same photo is 827 × 1063. Both print at exactly the same physical size. The higher number simply puts more detail into the same paper.
The formula is straightforward: millimetres ÷ 25.4 × DPI = pixels. 35 ÷ 25.4 × 600 ≈ 827. Everything else about print sizing follows from it.
The trap is that DPI is stored inside the file as a note to the printer, and most software does not write it. A file that is the right pixel size but carries no density information gets printed at whatever the printer assumes, which is how a correctly prepared photo comes out of a kiosk at the wrong physical size. Files exported here have the density written into the JPEG header explicitly, so the print comes out at the millimetres it claims.
Digital uploads follow different rules
Online application portals have their own limits, and they are not the same as the printed specification. The UK asks for at least 600 × 750 pixels and a file between 50 KB and 10 MB. The US online renewal accepts JPG, PNG, HEIC or HEIF between 54 KB and 10 MB. Neither of those matches the aspect ratio of the printed format, because the portals crop the photo themselves.
In practice: prepare the printed format first, and if the portal wants something different, upload what it asks for. Do not try to satisfy both with one file — they are answering different questions.
Printing a sheet instead of one photo
No photo lab sells you a single 35 × 45 mm print. What they sell is a standard photo print — 10 × 15 cm is the usual size, 9 × 13 and 13 × 18 also common — and the trick every photo studio uses is to fill that print with a grid of passport photos. A 10 × 15 cm sheet holds eight 35 × 45 photos with room for cut lines between them.
You pay for one print and cut out as many photos as you need. At kiosk prices this is a fraction of what a studio charges for the same eight photos, and the cut lines make the trimming a two-minute job with ordinary scissors.
- Export the sheet as a single image and print it as a normal photo, at its full size, with no scaling
- Turn off any “fit to page” or “borderless” option — both rescale the image and change the physical size of every photo on it
- Print on photo paper, glossy or matte; office paper is refused by many offices
- Cut on the lines, not around them, and leave no white border
- Measure one photo with a ruler afterwards — it should read exactly 35 by 45 mm
Home printing
It works, with two conditions: photo paper, and scaling turned off. An A4 sheet of photo paper holds far more than eight photos, so it is worth doing if you need copies for several applications at once. What ruins home prints is the printer dialogue: “fit to page”, “scale to fit” and “shrink oversized pages” all silently resize the image, and a photo printed at 96 per cent is the wrong size on every dimension.
Print one test sheet and measure it before printing the rest. A ruler on the paper is the only reliable check — the preview on screen tells you nothing about physical size.