Converting centimetres to pixels
Photo specifications are published in physical units because they were written for print, while uploads need pixels. The conversion depends entirely on DPI — dots per inch — and there is no single right answer without it.
The formula is: pixels = (mm ÷ 25.4) × DPI. So 35mm at 300 DPI gives (35 ÷ 25.4) × 300 = 413 pixels, and 45mm gives 531. At 600 DPI you would get 827 × 1063.
| DPI | Pixel size | Typical use |
|---|---|---|
| 150 DPI | 207 × 266 px | Screen only — too low for print |
| 300 DPI | 413 × 531 px | Standard print requirement |
| 600 DPI | 827 × 1063 px | High-quality print, some embassies |
Which countries use 3.5 × 4.5 cm
The UK, all Schengen countries, Australia, New Zealand, Japan, South Korea, Singapore, Thailand, the Philippines, India, Turkey, South Africa, Brazil and most of the rest of Europe and Asia.
The main exceptions are worth knowing. The United States uses a 2 × 2 inch square. Canada uses 50 × 70mm. Malaysia uses 35 × 50mm — the same width but 5mm taller, which is easy to miss. Indonesia and Vietnam use 4 × 6cm for visa photos. India moved from 2 × 2 inches to 35 × 45mm in February 2026.
Frequently asked questions
- How many pixels is 3.5 x 4.5 cm?
- 413 × 531 pixels at 300 DPI, which is the standard print requirement. At 600 DPI it is 827 × 1063.
- Is 3.5 x 4.5 cm the same as 35 x 45 mm?
- Yes, identical — 1 cm is 10mm. Specifications are written both ways.
- What DPI should I use?
- 300 DPI unless your authority says otherwise. It is the near-universal minimum for print. Only use 600 if it is specifically required, and only if your source photo genuinely has that much detail.
Sources & disclaimer
The specifications on this page were taken from the sources below on the dates shown:
- ICAO Doc 9303 — Machine Readable Travel Documents — checked October 2026
Please verify before you submit. Government photo requirements change without notice and are not always announced — India replaced its 2 × 2 inch passport photo standard in February 2026, for instance. The information here reflects those sources as of the dates given and may since have become out of date, and requirements can also differ between individual embassies and consulates. It is provided for general guidance only, with no warranty of accuracy or completeness, and Instant Image Resizer accepts no liability for rejected applications, fees or other losses arising from its use. Always confirm the current requirements with the issuing government authority before submitting your application.