Passport photo pixels, DPI and print size

Last reviewed 2026-08-29 · AppsOverflow LLC

The conversion, in one line

Millimetres, pixels and DPI are tied together by one piece of arithmetic: pixels = millimetres ÷ 25.4 × DPI. An inch is 25.4 mm, DPI is how many pixels you put in each inch, and the pixel count falls out of the two. On the sizes people are actually asked for:

2 × 2 in at 300 DPI is 600 × 600 px. At 600 DPI it is 1200 × 1200 px.
35 × 45 mm at 300 DPI is 413 × 531 px. At 600 DPI it is 827 × 1063 px.
50 × 70 mm, Canada's printed size, is 591 × 827 px at 300 DPI.

The confusion comes from the numbers being aimed at two different audiences. An upload portal states its rule in pixels, because it will never print anything. A passport office states its rule in millimetres, because a printed photo gets held against a ruler. DPI is the hinge between them, and it lives inside the file as metadata you cannot see by looking at the image — which is why a file with exactly the right pixel dimensions can still print at the wrong physical size.

Every common size, converted

The verified printed sizes from our country pages, through the same line. These are what a print needs at that density, not upload rules — most of these authorities publish no pixel count at all.

Printed size	Used by	At 300 DPI	At 600 DPI
2 × 2 in (50.8 mm)	United States, US visa	600 × 600	1200 × 1200
35 × 45 mm	UK, France, Germany, Netherlands, Schengen practice	413 × 531	827 × 1063
50 × 70 mm	Canada	591 × 827	1181 × 1654
45 × 35 mm	Mexico	531 × 413	1063 × 827
5 × 5 cm	Brazil, at a consulate	591 × 591	1181 × 1181
32 × 26 mm	Spain, per Real Decreto 896/2003	378 × 307	756 × 614
4 × 6 in sheet	Print paper, not a photo size	1200 × 1800	2400 × 3600

The conversions rarely land on whole pixels: 45 mm at 300 DPI is 531.5 px, so both 531 and 532 circulate for the same photo. Where a portal states an exact figure, use its figure.

Uploads in pixels, prints in millimetres

Software receiving a file cannot know how large you meant the picture to be, so it counts pixels and sets a floor high enough that a face is measurable. A clerk with a ruler needs millimetres. Countries accepting both routes publish both numbers, and the two are not translations of each other.

The UK asks for a printed photo of 35 × 45 mm, and for the digital route at least 600 × 750 px in a file of 50 KB to 10 MB (GOV.UK). Canada publishes 50 × 70 mm for print and, digitally, 3:2 portrait at 1800 × 1200 px or more, 200 KB to 5 MB, head at 45–50 per cent (Canada.ca). In each case the pixel spec describes a different rectangle from the printed one, which catches anyone assuming one is the other scaled up.

A third form appears in print rules: the Netherlands states a density rather than a pixel count, asking for 400 DPI or better (Rijksoverheid). At 400 DPI, 35 × 45 mm means 551 × 709 px.

Head height survives the conversion

Every head-height rule in our verified set is a proportion of the frame, so it survives the conversion. A UK head of 29–34 mm in a 45 mm frame is 64–76 per cent, still 64–76 per cent in a 750-pixel-tall file, or 480 to 570 px. The photo checker reports millimetres whatever the pixel dimensions are; head size is the measurement that fails most photos explains how to measure it.

DPI is a number stored inside the file

Pixel dimensions are the image. DPI is a label attached to it saying how large those pixels should be once they are ink. Change the label and not a single pixel moves, but the printed size changes completely.

Take a 600 × 600 px file. At 300 DPI it prints 2 in square, a US passport photo. At 600 DPI the same file prints 1 in square. At 72 DPI, the fallback a lot of software uses when a file says nothing, it prints 8.33 in square — bigger than the paper. The image was never wrong. The label was missing.

Missing is the normal case. A JPEG stores density in its JFIF header, and that header has a units field which can say "no units", meaning the numbers describe an aspect ratio rather than a physical size. A PNG records physical size in an optional chunk plenty of software never writes. A browser canvas, which is how most in-browser tools export, produces exactly that: a JPEG declaring no unit and a PNG with no physical size. Something downstream then assumes a density, and 72 DPI is a common assumption.

This failure looks like a printer fault and is not one

If prints came out the wrong size while looking perfect on screen, check the file's declared DPI before reprinting at a guessed scale. A dialogue offering "fit to page" or "scale 25%" is compensating for a density the file never declared, and a scaled print is no longer the size you measured. Print at 100 per cent, from a file carrying its own density. Our export writes the real density in, and the 4 × 6 template lays the sheet out at true physical size; printing on 4 × 6 paper covers the trimming risk that comes next.

Worked example: the US DS-160 upload

The US visa application wants a square colour photo between 600 × 600 and 1200 × 1200 px, with the head 25–35 mm chin to crown, stated as 50–69 per cent of the frame (travel.state.gov). Read that range against the print: 600 × 600 is a 2 × 2 in photo at 300 DPI and 1200 × 1200 is the same photo at 600 DPI. The portal is not offering a choice of sizes. It is accepting one 2 × 2 photo at any density from 300 to 600 DPI.

Aim near the top. A 1200 × 1200 file downsamples cleanly; a 600 × 600 file sits on the floor, so any later crop drops it below.

The trap is a printing one. A 1200 × 1200 file labelled 300 DPI prints as a 4 in square. Correct upload, useless print. If you need an upload and prints from the same session, export them separately rather than sending one file to both jobs — the DS-160 tool for the upload, the US passport photo tool for the print. Is a visa photo the same as a passport photo? covers where else the routes diverge.

Worked example: the UK digital photo

GOV.UK asks for at least 600 × 750 px in a file of 50 KB to 10 MB, and separately for printed photos of 35 × 45 mm taken in the last month, two identical copies. The pixel figure is a floor, not a shape. Crop to the printed 35 × 45 proportion, make it 600 px wide, and the height lands at 771 px, comfortably over the 750 minimum. Force an exact 600 × 750 instead and you have a 4:5 rectangle where the printed standard is 7:9 — workable for the upload, wrong the moment anyone prints it.

The 50 KB floor catches people, because every instinct says smaller is safer. A heavily compressed 600 × 750 JPEG can land under it. If your export comes out too small, raise the JPEG quality or the pixel dimensions rather than padding the file; when a portal says your file is too big covers both directions. The UK tool targets 35 × 45 mm with the head at 29–34 mm, inside that KB window.

When the number you have is wrong

Three different problems get called "wrong size", and the fixes are not interchangeable.

Right shape, too many pixels. Downscale. A 4000 × 4000 crop resampled to 1200 × 1200 loses nothing visible.
Right shape, too few pixels. No honest fix exists. Upscaling invents pixels rather than recovering them and reads as soft. Reshoot closer, or with a longer lens — taking a passport photo with a phone covers the framing that leaves enough to crop from.
Wrong shape. Recrop. Never stretch to fit a ratio: a distorted face is visible, and the head measurement it produces is meaningless.

If only the printed size is wrong, the fix is metadata, not pixels: rewriting the DPI without resampling changes the physical dimensions and leaves the image identical.

Resizing is allowed. Sharpening it back is not

Cropping and resizing are what the authorities ask for. Correcting the image is a different act, and several prohibit it in their own words. Canada publishes a zero-tolerance list naming brightness, contrast, colour and sharpness corrections, background replacement, filters and AI tools. GOV.UK requires the photo be "unaltered by computer software". The State Department instructs applicants not to change the photo using computer software, phone applications or filters, or artificial intelligence, and says it checks photos for AI use. So when a downscale leaves a photo looking soft, the answer is a better original, not a sharpening slider. The rule that broke every AI passport photo tool has each authority's wording.

What to check before you upload or print

For an upload: pixel dimensions against the portal's range, file size against both its floor and its ceiling, colour rather than greyscale, and the head as a percentage of frame height. For a print: the physical size the file declares, a print dialogue set to 100 per cent, and a ruler against the photo once it comes out.

Our photo checker measures head height and eye line in millimetres against the published range for your country, and reports resolution, sharpness, exposure, lighting and background. It crops and measures; it does not retouch your face. None of that is a promise of acceptance — only the issuing authority decides that, and the reasons photos get rejected is worth reading whichever route you take.

Everything here runs in your browser, with no upload, no account, no watermark and no limit. There is also a free iOS app, Passport Photo: Photo Maker ID — free to download, with one free export before it asks for Pro. The website is the unlimited one.

The office you apply to makes the final decision. This page reports what the authorities publish and links to their pages where we could reach them; it is not legal advice and it is not a guarantee of acceptance.

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Passport Photo: Photo Maker ID does this on iOS with the phone's own camera and an on-device background tool. It is free to download and the first export is free; after that it asks for Pro. This website has no limit.