Pixels per inch — diagonal pixels divided by diagonal inches.

Why odd resolutions like 1366×768?

They are common bins approximating 16:9 used by manufacturers.

Aspect Ratio & PPI

Provide the aspect ratio and one dimension; the other is calculated.

Simplify aspect ratios, compute missing dimensions, and calculate display PPI & physical size.

Ratio W Ratio H Width (px) Optional — if set, height will be computed. Height (px) Optional — if set, width will be computed.

Simplified ratio Decimal Computed width Computed height

Width	Height

How do I compute the missing dimension?
Enter the ratio and either width or height; the tool calculates the other side.

What is PPI?
Pixels per inch: diagonal pixels ÷ diagonal inches. It reflects display sharpness.

Why do some widths look odd (e.g., 1366×768)?
They are common panel bins close to 16:9; manufacturers use rounded pixel grids.