Pixels at 300 DPI
Thirty millimetres converts to about 354 pixels and forty millimetres converts to about 472 pixels. Whole-pixel rounding is normal and does not change the intended print size when the file is printed at 300 DPI without scaling.
Why document instructions still matter
Some identity cards, permits and visas use 30×40 mm, but there is no universal head-height or background requirement for this rectangle. Find the issuing authority’s current specification before cropping.
Workflow
- Confirm that the requested size is exactly 30 mm wide by 40 mm high.
- Upload and position the original photo.
- Generate the crop and inspect the full head and shoulders.
- Download the single photo or print sheet.
- Verify any separate JPEG, KB, colour or submission rules.
What is not checked
The tool does not remove backgrounds, change appearance, detect shadows or guarantee approval. The positioning oval is a general visual aid only.
Reviewed July 26, 2026. See our conversion method. Related: 1×1 maker · 50×70 maker.