Print Pixel & DPI Calculator
Last updated: 2026-06-25
Print pixels = length (inches) × DPI. Divide cm by 2.54 or mm by 25.4 to get inches, then multiply by DPI.
Example: a 3 × 4 cm print at 300 DPI needs about 354 × 472 pixels. (For reference.)
Print pixel calculation
Pixels needed for print
0 × 0 px
| Item | Value |
|---|
Converted using 1 inch = 2.54 cm = 25.4 mm. Actual printed size may vary with printer settings and margins.
How to use
- Choose direction — select Size → pixels or Pixels → size.
- Enter values, unit, and DPI — enter width and height, a unit (cm, mm, inch), and the print DPI.
- View the result — press Calculate to see pixels or size and the total pixel count.
How to calculate print pixels and DPI
The number of pixels you need for printing depends on the output size and the resolution (DPI). DPI is the number of dots (pixels) per inch, so convert the print size to inches and multiply by DPI to get the width and height in pixels.
| Conversion | Formula | Example |
|---|---|---|
| cm → px | cm / 2.54 × DPI | 3 cm @ 300 DPI → 354 px |
| mm → px | mm / 25.4 × DPI | 35 mm @ 300 DPI → 413 px |
| inch → px | inch × DPI | 2 in @ 300 DPI → 600 px |
| px → cm | px / DPI × 2.54 | 354 px @ 300 DPI → 3 cm |
ID photo printing is usually based on 300 DPI. For the same output size, a lower DPI means fewer pixels and a blurrier print, while a higher DPI is sharper. See mm sizes by use in the ID & passport photo size guide, and resize photos with the photo resizer.
Frequently asked questions (FAQ)
How do I convert cm to pixels?
Pixels = cm / 2.54 x DPI. Since 1 inch is 2.54 cm, for example 3 cm printed at 300 DPI is 3 / 2.54 x 300 = about 354 pixels. For mm, use mm / 25.4 x DPI.
What is DPI and what should I set it to?
DPI (dots per inch) is the print resolution, the number of dots printed per inch. Use 300 DPI for regular photo and ID printing, 350 DPI for high-quality printing, and 72-96 DPI for screen display.
Can I reverse-calculate print size (cm) from pixels?
Yes. Print size (inches) = pixels / DPI, and in cm it is pixels / DPI x 2.54. For example, a 1063-pixel image printed at 300 DPI is 1063 / 300 x 2.54 = about 9 cm.
Are DPI and PPI the same?
Strictly, PPI (pixels per inch) is the pixel density of a screen or image, while DPI is the ink dot density of a printer. For print pixel conversions they are usually treated as the same value, and this calculator treats them identically.
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Last updated: 2026-06-25