Pixel Density (PPI) Calculator

Calculate screen pixel density from resolution and diagonal size

Your result will appear here.

About the Pixel Density (PPI) Calculator

Pixel density describes how tightly display pixels are packed into a physical screen area, usually in pixels per inch. It helps compare sharpness between screens that have different resolutions and physical sizes.

Resolution alone is not enough to determine density. A 4K television and a 4K phone can have the same pixel count but very different PPI because the phone packs those pixels into a much smaller screen.

How to Use the Pixel Density (PPI) Calculator

  1. Enter horizontal resolution in pixels.
  2. Enter vertical resolution in pixels.
  3. Enter physical diagonal screen size in inches.
  4. Calculate diagonal pixel count and divide by diagonal inches to obtain PPI.

How the Calculation Works

Pixel diagonal = √(horizontal pixels² + vertical pixels²).

PPI = pixel diagonal ÷ physical diagonal in inches. This relationship assumes square pixels and that the stated diagonal corresponds to the active display area.

Worked example

Pixel Density (PPI) Calculator Worked Example

1920×1080 display with 24-inch diagonal

Pixel diagonal = √(1920²+1080²) ≈ 2,202.91 pixels. PPI ≈ 2,202.91÷24 = 91.8.

Result guide

Understanding Your Pixel Density (PPI) Calculator Result

A higher PPI means more pixels are packed into each inch, which generally allows finer detail at the same viewing distance. Perceived sharpness also depends on eyesight and viewing distance. PPI can also be translated into approximate pixel pitch by taking one inch divided by PPI. For example, a 100 PPI display has pixels spaced about 0.01 inch apart before considering subpixel structure.

Before you rely on the answer

Assumptions and Limitations

  • Pixels are square.
  • Diagonal size refers to the active screen area.
  • Resolution is the display’s native pixel grid.

Practical tip

Using This Result in Practice

Compare PPI together with normal viewing distance. Extremely high pixel density may provide little visible benefit when the screen is viewed from several metres away.

Related calculations

Useful Calculations to Continue With

If you want to compare resolution formats before considering physical size, use the Screen Resolution Calculator.

If you are preparing an image for physical printing rather than a display, use the Print DPI Calculator.

Common questions

Pixel Density (PPI) Calculator FAQ

What does PPI mean?

Pixels per inch, a measure of display pixel density.

Does higher resolution always mean higher PPI?

No. Physical screen size also affects pixel density.

Is PPI the same as DPI?

They are related concepts, but PPI usually describes displays while DPI is commonly used for printing.