Convert pixels to cm and back

Find out how big an image prints, or how many pixels you need for a print size, at any DPI. Read the pixel size straight from a photo, or type it in.

Calculations and photo sizes are read on this device. Nothing is uploaded, stored or logged.

How it works

Choose Pixels to size or Size to pixels.
Type the width and, if you like, the height, or pick a photo to read its pixel size.
Choose the DPI: 300 for photo prints, 150 for posters seen from a distance, 72 for screens.
Read the result in cm, mm and inches, and the megapixels.

The formula

Centimetres = pixels ÷ DPI × 2.54, because one inch is exactly 2.54 cm. So at 300 DPI, 300 pixels print 2.54 cm wide and 1,200 pixels print 10.16 cm. The other way, pixels = centimetres ÷ 2.54 × DPI: an A4 page (21 × 29.7 cm) at 300 DPI needs 2,480 × 3,508 pixels.

Which DPI to use

300 DPI is the standard for photo prints and documents that people look at up close; print shops and forms usually ask for it. 150 DPI is enough for posters and banners seen from a metre or more. 72 or 96 DPI only matters on screens, where the number of pixels is what counts. Passport photos at 300 DPI: 35 × 45 mm needs 413 × 531 pixels.

How big can I print my photo?

Pick the photo and keep 300 DPI: the result is the largest size it prints sharply. A 12-megapixel phone photo (4032 × 3024 px) prints about 34 × 26 cm at 300 DPI, or twice as wide at 150 DPI. Printing larger than that spreads the same pixels further, and the print looks soft.

Your photo stays on your device

When you pick a photo, only its width and height in pixels are read, on your device. The photo isn't uploaded or kept.

Worked examples

Pixels and printed size
Pixels	DPI	Centimetres	Inches
1,080	72	38.1	15
600	300	5.08	2
1,200	150	20.32	8
2,480	300	21	8.27
4,032	300	34.14	13.44

Frequently asked questions

Does changing the DPI change my image?

No. DPI is only an instruction for printing; the image keeps the same pixels. To change the pixels, use Resize Image.

Is DPI the same as PPI?

For this purpose, yes. PPI (pixels per inch) is the precise term for images, but print services and most software say DPI.

How many pixels is 1 cm?

At 300 DPI, about 118 pixels; at 96 DPI (screens), about 38 pixels.

Is my photo uploaded?

No. Only its pixel size is read, in your browser.

Last reviewed: October 3, 2026