Utility
CM to Pixel Converter
Convert cm, mm or inches to pixels at any DPI — the way Indian exam forms specify photo sizes.
Pixels
413 × 531 px
How to use this tool
- Enter the width and height your form specifies.
- Pick the unit (cm, mm or inch) it's given in.
- Choose the DPI — 300 is a safe default for exam photos.
- Read the pixel size instantly, then resize your image to match.
Common exam photo sizes
| Use | Physical | @ 300 DPI | @ 500 DPI |
|---|---|---|---|
| Passport / most exams | 3.5 × 4.5 cm | 413 × 531 | 689 × 886 |
| UPSC (square) | 3.5 × 3.5 cm | 413 × 413 | 689 × 689 |
| Signature | 4 × 2 cm | 472 × 236 | 787 × 394 |
| PAN (NSDL) | 2.5 × 3.5 cm | 295 × 413 | 492 × 689 |
Related tools
Frequently asked questions
How do I convert cm to pixels?
Pixels = (centimetres ÷ 2.54) × DPI. For example, 3.5 cm at 300 DPI is about 413 pixels. Enter your size and DPI above and it calculates instantly.
What DPI should I use for exam forms?
Most Indian exam portals assume 200 or 300 DPI. If the notification gives a pixel size directly, use that; otherwise 300 DPI is a safe default.
Why do forms give sizes in cm?
Passport-style photos are physically 3.5×4.5 cm, so notifications quote cm. Portals then check the pixel size, which depends on DPI — this tool bridges the two.