PPI Calculator
Enter resolution and diagonal size to get PPI, dot pitch and true pixel dimensions.
Standard — typical desktop monitor range
Frequently Asked Questions
How is PPI calculated?
PPI = √(width² + height²) ÷ diagonal inches. The square root gives the diagonal in pixels, and dividing by the physical diagonal gives pixels per inch.
What PPI do I actually need?
Around 110 PPI is typical for desktop monitors, 150–220 for laptops, and 300–460 for phones held close. Beyond your viewing distance’s limit, extra PPI is invisible.
What is dot pitch?
Dot pitch is the distance between pixel centres, in millimetres: 25.4 ÷ PPI. Smaller dot pitch means a sharper image.
Is PPI the same as DPI?
They are often used interchangeably for screens. Strictly, DPI refers to printer dots and PPI to display pixels; this calculator computes display PPI.
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