How is screen PPI calculated?

PPI is calculated using the Pythagorean theorem on pixel dimensions divided by diagonal inches: sqrt(width^2 + height^2) / diagonal.

Updated: August 2026 • Verified v1.2

Screen PPI & Display Geometry Calculator

Hardware & SystemsHardware

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PPI = sqrt(Width^2 + Height^2) / Diagonal_Inches

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Understanding Your Results

Calculates pixel density (PPI), dot pitch in millimeters, total megapixels, simplified aspect ratio, and recommended ergonomic viewing distance.

Practical Guidance & Next Steps

110 PPI is standard desktop sharpness (27" 1440p). 160+ PPI (27" 4K) provides crisp retina-like text clarity.

What is this?

A hardware display calculator that computes pixel density (PPI), pixel pitch, and visual acuity viewing distances for monitors, laptops, and mobile screens.

How does it work?

1. Enter screen resolution (Width and Height in pixels) or choose a preset (4K, 1440p, 1080p, Ultrawide). 2. Enter diagonal screen size in inches. 3. Instantly view PPI, dot pitch in mm, total megapixels, and ergonomic viewing distance.

Why use it?

Helps users choose the right monitor size and resolution for sharp text, gaming immersion, and design workflows.

Technical Scope & Calculation Limitations

Calculations assume standard rectangular square pixels (1:1 pixel aspect ratio).

Frequently Asked Questions

For standard desktop viewing (20-28 inches away), 108-110 PPI (like 27" 1440p) is considered good, while 160-220 PPI (like 27" 4K or MacBook displays) provides razor-sharp 'Retina' clarity.

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