🧮 PPI Calculator – Measure Pixels Per Inch & Pixel Density

Use our PPI Calculator to find pixel density in both PPI (Pixels Per Inch) and PPcm (Pixels Per Centimeter). This is perfect for screen designers, print experts, and anyone comparing display quality.

📏 How to Calculate PPI (Pixels Per Inch)

1. Use the Pythagorean Theorem:
   DiagonalPixels = √(Width² + Height²)
2. Divide by screen diagonal size in inches:
   PPI = DiagonalPixels / DiagonalInches

This formula works because pixels are square – meaning pixel density remains consistent in all directions.

🔍 Example Calculation

A screen with resolution 1920 x 1080 pixels and a 10-inch diagonal gives:

• DiagonalPixels = √(1920² + 1080²) = 2202.91
• PPI = 2202.91 / 10 = 220.29

So, this screen has a pixel density of 220.29 PPI.

📐 Pixels Per Square Inch (PPI²)

To find the number of pixels in one square inch:

PPI² = 220.29 × 220.29 = 48,528 pixels/in²

📏 Dot Pitch – Measuring Pixel Spacing

Dot pitch is the space between pixels (diagonally), calculated as:

Dot Pitch = (Diagonal Inches / Diagonal Pixels) × 25.4

Example: A 15.4″ screen with 3396 pixels → ≈ 0.1152 mm pitch

🔳 Aspect Ratio Explained

For a screen 1920 x 1080 px:

• • GCF = 120 → Ratio = 16:9
  • Also expressed as 1.78:1 by dividing both by 1080