How to use

Pick what you want to calculate, enter known values, then click Calculate.

Select a mode: Check DPI, Pixels required, Physical size, or Batch.
Enter pixels, DPI, and/or print size (choose inches/cm/mm). Use presets if needed.
Click Calculate and copy the output.

FAQ

Is DPI the same as PPI?

For these calculations, yes: both represent pixels (or dots) per inch used to relate pixels to a physical size.

Why do I see different DPI for X and Y?

It happens when pixel dimensions and physical dimensions don’t match the same aspect ratio; the tool shows both axes plus an effective value.

What DPI should I use for printing?

300 DPI is a common target for high-quality prints; posters viewed from farther away can often be lower.

Does this tool read DPI from an uploaded image?

No—this is a calculator. Enter the pixel dimensions and the intended physical size (or DPI) to compute the result.

How do I calculate pixels for A4 at 300 DPI?

Select A4 preset, set DPI to 300, use “Pixels required”, then calculate (typically 2480×3508 px).

Why doesn’t changing DPI in an editor change image quality?

Changing DPI metadata alone doesn’t change pixel count; quality depends on actual pixels available for the print size.

What batch formats does it accept?

Examples: “2480x3508 @300 dpi”, “300 dpi 8.5x11 in”, or “3600x2400 px 12x8 in” (one per line).