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DPI and PPI Calculator: Pixel Density and Print Size

This free calculator finds the pixel density (PPI) of a screen from its resolution and diagonal, the size an image prints at for a given DPI, and the pixel size you need to print at a chosen size.

By Debmedia Technologies LLP · Kolkata, India · Updated

What Is It and When Do You Need It?

Sharp prints and screens depend on pixel density. Photographers, designers and buyers all need to turn pixels into inches and back.

Choose what you want to find and fill in the boxes it needs.

How to Use This Tool

  1. Enter or paste your input in the box or boxes above.
  2. Choose the options, if there are any.
  3. Press the button to run the tool.
  4. Read the result and use the copy button where one is shown.

How the Calculation Works

Screen PPI is the pixel diagonal divided by the inch diagonal. Print size is pixels divided by DPI for each side, with a conversion to centimetres. Pixels needed is the print size in inches times the DPI.

Worked Example

A 1920 x 1080 screen that measures 24 inches across has 91.8 PPI. A 3000 x 2000 photo prints at 10 x 6.67 inches at 300 DPI.

Common Uses

  • Print orders.
  • Choosing a monitor.
  • Photo cropping.
  • Design files.

Tips and Common Mistakes

  • Aim for 300 DPI for close viewing.
  • Phone screens are often 400 PPI or more.
  • Measure the diagonal of the visible screen.
  • Check the first result against a case you already know, so you can trust the tool for the rest.
  • Nothing you type leaves your device. The work is done by your browser, so it also works with a slow connection once the page has loaded.

Next, you may need the megapixel calculator, aspect ratio calculator, JSON formatter and validator, CSV and JSON converter.

Everything runs in your browser. Nothing you type is uploaded, stored or sent to any outside service.

Frequently Asked Questions

PPI counts pixels per inch on a screen or image. DPI counts printed dots per inch. People often use them as the same thing.
300 DPI is the usual aim for sharp photos and magazines. 150 DPI is fine for posters seen from a distance.
The diagonal in pixels (the square root of width squared plus height squared) divided by the diagonal in inches.
Making an image bigger with software does not add detail. Start from the pixels you need.

Disclaimer: results are calculated in your browser from the numbers you enter. Check important results before you rely on them for money, health, safety or legal decisions.