Image size converter (px, cm, inches, KB)
Convert between pixels and cm/inches using DPI, then resize. For KB targets, compress after resizing.
Unit conversions
- pixels = inches × DPI
- inches = cm ÷ 2.54
- inches = mm ÷ 25.4
KB targets
- Compress after resizing to hit 100KB/200KB.
- Use WebP for smaller file sizes.
3 steps (using this workflow)
- Convert units to pixels using DPI.
- Resize to pixel dimensions.
- Compress to a KB target if needed.
Need a specific guide?
Use the links below for cm/inches, pixels, or KB targets.
Related guides
Print
Resize in cm/inches →Use this when a form or print brief gives physical measurements, so you can convert them into the right export size.
Converter
PX to CM converter →Use this when you already know the pixel dimensions, so you can report the print size in centimeters.
Millimeters
Resize in mm →Use this when an ID photo or print job specifies millimeters, so the final image matches the physical size exactly.
Pixels
Resize in pixels →Use this when a website or platform asks for exact pixel dimensions, so the canvas matches the required screen size.
File size
Resize in KB →Use this when the upload form caps file weight, so you can trim KB after setting the right dimensions.
FAQ
What does an image size converter do?
It converts between pixels, cm/inches, and KB targets.
Quick tip: Use DPI for physical units and compression for KB targets.
Common mistake: Mixing up pixels and KB—these are different concepts.
How do I convert inches/cm to pixels?
Pixels = inches × DPI. For cm, divide by 2.54 first.
Quick tip: Use 300 DPI for print.
Common mistake: Skipping DPI—size will be wrong.
How do I hit a KB file size?
Resize dimensions first, then compress with WebP/JPG.
Quick tip: Adjust quality to reach the target size.
Common mistake: Only resizing dimensions—KB may still be too large.
Do you upload my images?
No. Processing happens locally in your browser. Your files are not uploaded.
What size should I use?
Use the recommended size.
Which export format should I use?
JPG for photos, PNG for text/logos or transparency, WebP for smaller files (if supported).
Crop vs Pad — what is the difference?
Crop fills the target size (may cut edges). Pad fits the whole image and adds background/space.
How do I protect text and logos?
Keep important content centered and avoid placing critical text at the edges.
Can I batch resize?
Yes. Use the Batch Resizer to apply the same size to many images.