PPI Calculator

Pixels Per Inch Calculator

The higher the PPI, the sharper and more detailed the display appears, as more pixels are packed into each inch of the screen.

Screen 1:

Width:

Height:

Diagonal:

Add next screen to a comparison

Result:

PPI pixels per inch
PPI²
Total pixels
Total megapixels
Diagonal resolution
Dot pitch
Actual aspect ratio
Common aspect ratio

About this calculator

The PPI Calculator allows you to calculate and compare various display parameters for up to 30 screens.

This tool is useful for comparing display sharpness, image clarity, and screen quality across different devices.

It provides key metrics such as:

PPI (Pixels Per Inch) – Measures pixel density.
Total Pixels – The total number of pixels on the screen.
Megapixels – The screen resolution in megapixels.
Diagonal Resolution – The total number of pixels along the screen diagonal.
Dot Pitch – The distance between individual pixels.
Aspect Ratio – The ratio of width to height.
Common Aspect Ratio – Identifies the closest standard aspect ratio (e.g., 16:9, 4:3).

How to Use

Enter screen resolution (width × height in pixels).
Enter screen size (diagonal in inches).
Compare multiple screens by adding additional entries (up to 30).
View results for all selected parameters.

How to Calculate PPI

PPI (Pixels Per Inch) is a measure of pixel density, indicating how many pixels fit into one inch of a screen. A higher PPI value results in sharper and more detailed images.

Formula

The PPI of a display is calculated using the Pythagorean theorem to determine the diagonal resolution, then dividing by the screen size in inches:

$$ PPI = \frac{\text{diagonal\ in\ pixels}}{\text{diagonal\ in\ inches}} $$

Step-by-Step Calculation

Obtain the screen resolution – The $\text{width}$ and $\text{height}$ in pixels.
Obtain the screen size – The $\text{diagonal}$ in inches.
Calculate the diagonal resolution – Use the Pythagorean theorem:
$$ \text{diagonal\ in\ pixels} = \sqrt{\text{width}^2 + \text{height}^2} $$
Divide by the screen size – Compute the final PPI value:
$$ PPI = \frac{\text{diagonal\ in\ pixels}}{\text{diagonal\ in\ inches}} $$

Example Calculation

For a screen with a resolution of $1920 \times 1080$ pixels and a diagonal size of $24$ inches:

$$ \text{diagonal\ in\ pixels} = \sqrt{1920^2 + 1080^2} = \sqrt{3686400 + 1166400} = \sqrt{4852800} \approx 2202.91 $$
$$ PPI = \frac{2202.91}{24} \approx 91.79 $$

Thus, the screen has a pixel density of approximately 91.79 PPI.