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DPI / PPI Calculator

Calculate screen pixel density from resolution and diagonal size, or print density from pixels and inches.

Use positive dimensions. PPI describes screen pixel density; the print calculation gives pixels per printed inch, commonly called DPI.

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Screen pixel density

Screen PPI = sqrt(width² + height²) / diagonal in inches. A 1920 × 1080 display measuring 24 inches diagonally has about 91.79 PPI. Use the visible screen diagonal, not the outside size of its frame.

Print density and terminology

For print, divide the pixel dimension by its physical length in inches. PPI describes pixels per inch; DPI describes printer dots and is often used loosely for image print density. This calculation does not determine a printer’s actual dot pattern or guarantee print quality. All dimensions must be positive.

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