What this calculator does
Convert a physical width and height in centimetres or inches into required pixel dimensions. Reverse mode estimates print size from pixels and a chosen DPI/PPI.
DPI / Print Size Calculator
Plan the pixels. Print at the right size.
Enter dimensions and DPI manually to convert print size into pixels—or pixels into inches and centimetres. No image upload required.
Manual dimensions Two-way calculation No upload required
Calculate pixels and print size
Choose a direction, enter positive values, and get an instant result.
Pixel requirements are rounded to the nearest whole pixel. DPI is used here as the target print density.
Want to inspect an actual image and read its stored DPI metadata?Use our DPI Checker
How DPI and print-size calculations work
Formula
- Pixels = inches × DPI.
- Inches = pixels ÷ DPI.
- Centimetres = inches × 2.54.
Example
For 3.5 × 4.5 cm at 300 DPI: divide each measurement by 2.54, multiply by 300, then round. The result is approximately 413 × 531 px.
Quick answers
Frequently asked questions
Everything you need to know before you start.
How do I calculate pixels from centimetres and DPI?
Divide centimetres by 2.54 to get inches, then multiply by the target DPI. PixelKaro rounds the result to the nearest whole pixel.
How do I calculate print size from pixels?
Divide the pixel width and height by the target DPI/PPI to get inches. Multiply those inch values by 2.54 for centimetres.
Why can the pixel result differ by one pixel?
Physical measurements can produce decimal pixel values, but image dimensions must use whole pixels, so the calculator rounds to the nearest pixel.
Does changing DPI improve image quality?
No. A DPI value connects existing pixels to a print size; changing it alone does not create new image detail.
Is 300 DPI always required?
Not always. The suitable density depends on the printer, viewing distance and project requirements. Confirm the specification for your intended use.
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