Web & SEO

PPI Calculator — Free 2026

Calculate pixels per inch, total pixels, aspect ratio, and display quality rating from your screen resolution and size.

Width (pixels) Please enter a valid number.

Height (pixels) Please enter a valid number.

Diagonal Size (inches) Please enter a valid number.

Display Metrics

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Pixels Per Inch

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Total Pixels

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Aspect Ratio

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DPI Rating

How It Works

Enter resolution
Enter diagonal
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Understanding Pixels Per Inch

PPI (Pixels Per Inch) is a measure of pixel density — the number of individual pixels that fit within one linear inch of a display. Higher PPI means more pixels are packed into each inch, resulting in sharper text, smoother curves, and more detailed images. PPI depends on both the screen resolution (total number of pixels) and the physical screen size. A 4K resolution on a 27-inch monitor will have a different PPI than the same resolution on a 15-inch laptop screen.

PPI Ratings Explained

Displays with less than 100 PPI are considered Low density — individual pixels may be visible at normal viewing distances. Medium density (100-200 PPI) covers most standard desktop monitors. High density (200-300 PPI) provides noticeably sharper text and images, common in modern laptops. Retina-class displays (300+ PPI) pack so many pixels that the human eye cannot distinguish individual dots at typical viewing distance, delivering the crispest possible display quality.

Common Screen PPI Values

A typical 24-inch 1080p monitor has about 92 PPI. A 27-inch 4K display achieves approximately 163 PPI. The iPhone 15 Pro has 460 PPI, and the MacBook Pro 14-inch reaches about 254 PPI. For web designers, understanding PPI is essential for creating assets that look sharp across devices. Check our Image Resizer for preparing images at different resolutions, or use the Unit Converter for other measurement conversions.

Frequently Asked Questions

What is PPI?

PPI stands for Pixels Per Inch. It measures the pixel density of a screen — how many pixels fit into one linear inch. Higher PPI means sharper, more detailed images and text.

What is the difference between PPI and DPI?

PPI (Pixels Per Inch) refers to screen display density, while DPI (Dots Per Inch) technically refers to print resolution. In common usage, they are often used interchangeably when discussing screens.

What PPI is considered Retina?

Apple considers a display "Retina" when it has enough PPI that individual pixels cannot be distinguished at a normal viewing distance. This is generally 300+ PPI for handheld devices and 220+ PPI for laptop screens.

How is PPI calculated?

PPI is calculated using the formula: PPI = sqrt(width^2 + height^2) / diagonal. First, compute the diagonal resolution in pixels using the Pythagorean theorem, then divide by the physical diagonal size in inches.