What Is My Screen Resolution

PPI Calculator

Compute pixels-per-inch from pixel dimensions and diagonal inches.

Enter pixel width/height and diagonal size (in inches) to calculate PPI. Or click Use my device to auto-fill pixel dimensions (best-effort). Diagonal (inches) is the monitor / screen size (the printed/advertised diagonal of your display).

Results
PPI (X)
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PPI (Y)
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PPI (Avg)
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Pixel Diagonal
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Total Pixels
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Megapixels (MP)
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PPI² (pixels per in²)
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Dot Pitch (mm)
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Aspect Ratio (common)
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Aspect Ratio (actual)
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Notes: PPI (pixels per inch) = diagonal pixels / diagonal inches. Enter the physical diagonal of your monitor/screen (for example the number printed in the monitor specs: 15.6", 24", etc.). All three fields are required to compute PPI.

What Is PPI (Pixels Per Inch)?

PPI (Pixels Per Inch) is a measurement of pixel density on a digital screen. It tells you how many pixels are packed into each inch of your display. Higher PPI means sharper text, clearer images, and smoother graphics.

PPI depends on two main factors:

  • Screen resolution — total number of pixels (e.g., 1920 × 1080)
  • Screen size — physical diagonal measurement in inches (e.g., 13.3")

A PPI Calculator uses these values to determine the sharpness and visual quality of your screen.

Why PPI Matters

PPI is important because it directly affects how crisp and detailed your display looks.

  • Sharper text and reduced eye strain
  • Higher image and video clarity
  • More detail for design, photo editing, and creative work
  • Smoother UI elements with less pixelation
  • Better gaming and 3D rendering experience

Modern Retina and high-density displays often exceed 200–300+ PPI, resulting in ultra-sharp visuals.

What a PPI Calculator Does

A PPI Calculator typically shows:

  • Your screen resolution
  • Your display size in inches
  • The calculated PPI (pixel density)
  • Classification: low-PPI, standard-PPI, or high-PPI display
  • Pixel density comparison with Retina standards

Why Use a PPI Calculator?

You may want to calculate PPI to:

  • Check display sharpness and quality
  • Compare two or more monitors or devices
  • Choose the right screen for gaming or design work
  • Verify if your display meets Retina or high-density criteria
  • Optimize graphics and UI elements for your screen

The PPI formula

Pixels per inch is calculated from a display’s resolution and its physical diagonal size. First find the diagonal in pixels with the Pythagorean theorem, then divide by the diagonal in inches:

PPI = √(width² + height²) ÷ diagonal (inches)

Example — a 24-inch 1920 × 1080 monitor:

√(1920² + 1080²) = √(3,686,400 + 1,166,400) = √4,852,800 ≈ 2203 px
2203 ÷ 24 ≈ 92 PPI

Enter your resolution and physical diagonal in the calculator above and it does this instantly.

Screen PPI vs print DPI

PPI and print DPI are related but serve different goals. On screen, PPI describes how sharp a display looks. In printing, DPI describes how many ink dots per inch a printer lays down. When preparing images:

Use caseRecommended densityWhy
Web / screen images72–96 PPIScreens render in CSS pixels; extra density is wasted unless serving Retina
Retina / high-DPR web144–192 PPI2×–3× sources keep images crisp on dense screens
Standard photo prints300 DPIThe print industry standard for sharp detail
Large posters / banners150 DPIViewed from a distance, so lower density is fine

Frequently asked questions

How do I calculate PPI?

Divide the diagonal resolution in pixels — √(width² + height²) — by the screen’s diagonal size in inches. For example, a 27-inch 2560 × 1440 monitor is about 109 PPI.

What PPI do I need for printing photos?

300 DPI is the standard for sharp photo prints viewed up close. Large prints seen from a distance, like posters, can use 150 DPI without a visible loss of quality.

Is PPI the same as DPI?

They’re used interchangeably online, but strictly: PPI (pixels per inch) measures screen density, while DPI (dots per inch) measures printer output. A screen has a PPI; a print has a DPI.

Does higher PPI mean a better display?

Higher PPI looks sharper, but only up to the point your eyes can resolve at your viewing distance. Beyond that the extra pixels give no visible benefit while demanding more GPU power.

Why is the calculator’s PPI only an estimate without my diagonal?

Browsers report CSS pixels, and CSS defines 1 inch as 96 CSS pixels — which rarely matches your monitor’s real physical inch. Entering your true diagonal size lets the calculator return an exact PPI instead of an estimate.