How to Resize an Image in cm, mm or Inches | Bsbshs
Open the tool →Resizing an image sounds simple until a form asks for a photo that is exactly 3.5 by 4.5 centimetres at 300 DPI. Pixels, centimetres, and DPI all matter — here is how to resize an image to exact real-world dimensions the right way.
Pixels vs centimetres vs DPI
Screens think in pixels. Print thinks in physical size (cm, mm, inches). The bridge between them is DPI (dots per inch) — how many pixels are packed into each inch of print. The same 600×600 pixel image can print as a tiny sharp stamp at 600 DPI or a large soft square at 72 DPI. So to resize for print, you set both the physical size and the DPI.
How to resize to exact dimensions
Using a free browser tool like the resizer on Bsbshs:
- Open the Resize tool and add your image.
- Choose your unit — pixels, cm, mm, or inches.
- Enter the width and height. For print, set the DPI too (300 is standard for photos).
- Download the resized image at the exact size you need.
Why DPI matters for print
If a passport photo must be 3.5×4.5 cm, that physical size needs enough pixels to look sharp on paper. At 300 DPI, 3.5 cm is about 413 pixels, so the tool produces a 413×531 image. Print that and it is crisp. Provide too few pixels and the photo looks blurry or blocky when printed. A good resizer calculates the pixels for you once you enter the size and DPI.
Keep the aspect ratio (or don't)
Stretching an image to a shape that doesn't match its original makes faces and objects look squashed. Most resizers offer a lock-aspect option so width and height scale together. Turn it on to avoid distortion; turn it off only when a form demands an exact shape and you have cropped the image to suit.
Common size presets
- Passport photo — 3.5 × 4.5 cm at 300 DPI (India, UK, EU).
- US visa photo — 2 × 2 inches at 300 DPI.
- Social media — set pixels directly; DPI does not matter.
- Print at home — set cm or inches with 300 DPI for crisp results.
Resize down, not up, for quality
Making an image smaller keeps it sharp. Making it much larger than the original cannot add detail that was never captured, so it looks soft. If you need a large print, start from the highest-resolution original you have.
Doing it privately
Resizing an ID photo or personal picture should not require uploading it. A browser-based resizer processes the image on your device, so your photo never leaves your computer or phone.
Frequently asked questions
Can I resize in centimetres or inches?
Yes — choose cm, mm, or inch and set the DPI so the physical size is accurate for print.
What DPI should I use?
Use 300 DPI for photos and print. For screen-only use, DPI does not matter — just set pixels.
Will resizing distort my image?
Not if you keep the aspect ratio locked. Unlock it only when a form requires an exact shape.
Is it private and free?
Yes — a browser tool like Bsbshs is free and never uploads your image.
Summary
To resize an image correctly, decide whether it is for screen (set pixels) or print (set cm/mm/inches plus 300 DPI), keep the aspect ratio locked to avoid distortion, and resize down rather than up for the sharpest result. Do it in your browser and your photo stays private.
Open the tool →