Free pixels ↔ cm / mm / inches converter
Convert pixels to cm, mm or inches at any DPI — and back. Check that your photo file really matches the printed size. The formula is shown on the page.
Loading interactive tool…
How it works
- 1Type a value in any unit (px, cm, mm, in).
- 2Pick your DPI (300 is the safe default).
- 3Read the converted value in the other units.
Frequently asked
What's the formula for pixels to cm?
cm = (pixels ÷ DPI) × 2.54. Example: 1200 pixels at 300 DPI = (1200 ÷ 300) × 2.54 = 10.16 cm.
And mm to pixels?
pixels = (mm ÷ 25.4) × DPI. Example: 35 mm at 300 DPI = (35 ÷ 25.4) × 300 ≈ 413 pixels.
Why does the result have decimals?
Pixels are integers but the conversion factor (25.4 mm per inch) isn't. We round the pixel output to the nearest integer (since you can't have a fractional pixel) and show physical dimensions to 0.1 mm.
Skip the unit conversion entirely
Anfas.Pro measures and crops your photo directly to the document's real-world size — no manual pixel math.