Passport Photo DPI Requirements
Searches for a "passport photo DPI" usually hit the wrong idea: there is rarely a DPI number you must set. What actually matters is pixel size for online uploads and print resolution for paper. This guide explains how millimetres, pixels and DPI relate, with the official UK and ICA standards. Verified October 2026.
The 15-second answer
There is no universal DPI you must stamp on a passport photo. Online portals ask for pixel dimensions (ICA Singapore, for example, accepts 400 × 514 px). For a printed photo, aim for about 300 DPI, which is the ordinary print resolution. The two are linked by the physical size of the photo.
What DPI actually means
DPI (dots per inch) describes print resolution — how much detail is packed into each inch of paper. A digital file does not really "have" a DPI until you decide how big to print it; what it has is a pixel width and height. That is why online forms ask for pixels, not DPI.
Millimetres, pixels and DPI together
The three are connected by one formula:
pixels = (millimetres ÷ 25.4) × DPI
| Photo size | At 300 DPI |
|---|---|
| 35 × 45 mm | 413 × 531 px |
| 50 × 70 mm | 591 × 827 px |
| 2 × 2 in (50.8 mm) | 600 × 600 px |
So a "35 × 45 mm passport photo" is the same instruction as "413 × 531 px at 300 DPI" — the size expressed two ways.
What the official standards say
- UK (HMPO): the photo standards follow ICAO specifications and set out what the image must look like — they do not mandate a DPI figure; the working target for print is about 300 DPI.
- ICA (Singapore): the recommended dimensions for an online submission are 400 × 514 px — a pixel instruction, not a DPI one.
Why uploads still get rejected
Almost always because the pixel dimensions are too small or the file is over-compressed — not because of a DPI setting. Start from an image that is at least the required pixel size and keep it sharp. Do not take a tiny photo and upscale it: that adds no real detail.
Getting it right
See the digital file requirements guide for file format and size rules, and the passport photo checker to test your picture. For a photo you will print, lay it out with the print sheet, and start from the photo size chart for the exact dimensions of your document.
Frequently asked questions
Is there a required DPI for a passport photo?
Not as a number stamped on the file. Online portals ask for pixel dimensions (for example, ICA Singapore accepts 400 x 514 px). DPI matters mainly for printing, where about 300 DPI is the usual target.
What is 300 DPI in pixels for a 35 x 45 mm photo?
413 x 531 pixels. The conversion is pixels = millimetres / 25.4 x 300, so 35 mm becomes 413 px and 45 mm becomes 531 px.
What about a 2 x 2 inch photo at 300 DPI?
600 x 600 pixels. Two inches is 50.8 mm, and 50.8 / 25.4 x 300 = 600.
Does the UK require a specific DPI?
UK HMPO photo standards follow ICAO specifications and deal with the image and its quality rather than mandating a DPI figure; the practical target for a printed photo is around 300 DPI.
Why do some uploads get rejected for size?
Usually because the pixel dimensions are too small (or the file is too compressed), not because of a DPI number. Check the portal's pixel requirement and keep the image sharp.
What DPI should I scan at, or export at?
Export or scan so the image is at least the required pixel size; 300 DPI is the safe convention for print. Do not upscale a small photo and expect it to pass.
Check your photo free → Photo size chart →
Source note: the UK standards reference is His Majesty's Passport Office photo standards (v51.0, published 19 January 2026), which follow ICAO specifications; the 400 × 514 px online figure is from ICA Singapore's photo guidelines. The pixel conversions are arithmetic at 300 DPI (pixels = mm ÷ 25.4 × 300). Always confirm the exact requirement on your destination's official page before submitting.
Browse all passport guides or the photo size chart.