Image Size & DPI Calculator
Convert pixels, print dimensions, centimetres, inches and DPI.
About this tool
This free image size and DPI calculator links pixels, centimetres, inches and print resolution. It answers three questions: how large can I print this image, how many pixels do I need to print at a given size, and what resolution do I get from a given size. It is useful for photographers, designers, print shops and businesses preparing posters, flyers or menus.
Choose the calculation and the unit, centimetres or inches, and only the relevant fields appear, with the result updating as you type. Shortcut buttons fill in 72, 96, 150 or 300 DPI in one click. When you switch units, the physical dimensions you entered are converted automatically. If the horizontal and vertical resolutions differ, the tool shows both values and points it out.
- 3 modes: pixels, print size, DPI
- Centimetres or inches
- Shortcuts for 72, 96, 150 and 300 DPI
- Result updates as you type
- Warning when proportions do not match
How to use it
- Choose the Calculation, for example Pixels → print size.
- Select the Physical unit: cm or in.
- Fill in the pixel dimensions, physical size or DPI requested.
- Read the Result, which updates automatically.
Frequently asked questions
What resolution should I use for printing?
300 DPI is a common reference for high-quality prints viewed up close, such as photos or flyers. For a large poster viewed from a distance, a lower resolution such as 150 DPI is often enough.
What is the difference between DPI and PPI?
PPI (pixels per inch) describes the pixel density of an image, while DPI (dots per inch) refers to the ink dots a printer lays down. The terms are often used interchangeably; this tool calculates pixels per inch.
Do I need to upload my image?
No. You only enter its pixel dimensions; no file is needed and all calculations run in your browser.
Is the DPI calculator free?
Yes, it is free with no sign-up or account.