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Screen PPI Calculator

Calculate screen pixel density, active width and height, and pixel pitch from resolution and diagonal.

Your numbers

Make it your own
Updates as you type
Pixels per inch
91.7878ppi

Calculated from your inputs · rounded for display

Physical width20.9178in
Physical height11.7663in
Pixel pitch0.27672523mm

Assumes square pixels and that the entered diagonal is the active display area. PPI is different from operating-system scaling and printer DPI.

Your calculation, step by step

No black boxes
  1. Pixel diagonal = √(1920² + 1080²).
  2. PPI = pixel diagonal / 24 inches.

How to use this calculator

  1. Enter your own values in the labeled fields. Check the units and assumptions before comparing results. Only the fields needed for your selected calculation mode are shown.
  2. Your answer updates automatically. Review the calculation steps to see exactly how it was calculated.
  3. Copy, share, save, or download your result. Saved inputs stay on this device.

How the calculation works

PPI = √(horizontal²+vertical²) / diagonal inches

The geometry assumes square pixels and a diagonal measured across the active image area. Physical dimensions follow from the pixel aspect ratio. PPI describes screen density and does not specify operating-system scale, viewing distance or printer resolution. Review the units, period and assumptions before comparing scenarios. Displayed values are rounded, while the underlying calculation retains its available precision.

A worked example

A 1,920 × 1,080 display with a 24-inch active diagonal has √(1920²+1080²)/24 ≈ 91.7878 PPI.

Reading your result

Use the main result together with its units and supporting figures. Display values are rounded; calculations keep their underlying precision. A change in inputs or assumptions can change the answer. Compare the step-by-step working with your intended use before relying on an estimate.

Frequently asked questions

What assumptions does this calculation use?

The geometry assumes square pixels and a diagonal measured across the active image area. Physical dimensions follow from the pixel aspect ratio. PPI describes screen density and does not specify operating-system scale, viewing distance or printer resolution.

Can I save or check a scenario?

The result includes the working and supporting values. Save and Restore keep inputs on this device; Copy, Download and Print export the result. Sharing a scenario explicitly includes the inputs in its link.

Sources & methodology

This calculator uses the mathematical identity and assumptions stated above. No current rates, prices, or external data are loaded. Conversion tools use international unit definitions.

Formula review: October 24, 2026. Read our methodology.