Photo Size Converter
Convert between mm, inches and pixels at any DPI.
Pixels = millimetres ÷ 25.4 × DPI. 300 DPI is the usual print resolution; online forms often ask for pixels directly.
| Unit | Width | Height |
|---|---|---|
| mm | 35 | 45 |
| cm | 3.5 | 4.5 |
| in | 1.378 | 1.772 |
| px @ 72 DPI | 99 | 128 |
| px @ 96 DPI | 132 | 170 |
| px @ 150 DPI | 207 | 266 |
| px @ 200 DPI | 276 | 354 |
| px @ 300 DPI | 413 | 531 |
| px @ 600 DPI | 827 | 1063 |
Aspect ratio 0.778 : 1 · 413 × 531 px at 300 DPI.
Open this size in the editorNothing to upload here — this is a calculator. Sizes for specific countries and documents are listed with sources on the countries pages.
About this tool
Photo requirements are written in three different languages — millimetres, inches and pixels — and a form may use any of them. The Photo Size Converter translates between them at any DPI, shows the pixel dimensions at every common resolution, and can open the editor with the size already set.
The conversion is the exact one used by every tool on this site: pixels = millimetres ÷ 25.4 × DPI, with 25.4 mm to the inch. There is no upload here; it is a calculator.
How it works
- Enter a width and height, or pick a common size from the list.
- Choose the unit you have and, for pixels, the DPI you were given.
- Read the table, then open the editor with that size if you want to make the photo now.
Good to know
- If a form gives only pixels, the physical size is only meaningful together with a DPI — 600 × 600 px is 2 × 2 in at 300 DPI but 4 × 4 in at 150 DPI.
- "Passport size" is not one size: 35 × 45 mm in most of the world, 2 × 2 in in the United States, 50 × 70 mm in Canada, 33 × 48 mm in China.
- For printing, 300 DPI is the usual standard; screens and web portals ignore DPI and only count pixels.
Questions about this tool
What does DPI mean for a digital photo?
Dots per inch: how many pixels are placed along one inch when printed. It links a pixel size to a physical size. A file stores DPI as metadata, which print software reads; a web portal typically ignores it.
Why do my pixel numbers differ slightly from a form?
Rounding. 35 mm at 300 DPI is 413.39 px, which rounds to 413; some authorities publish 413 and others 414. A difference of one pixel is normally within tolerance — but if a form states an exact number, enter that number in the editor.
DocPixEdit provides technical guidance and automated checks based on the requirements and sources listed on this page. Requirements can change, and final acceptance is determined by the relevant authority. Always verify current requirements before submission.