Pixel Density Calculator

PPI Formula:

\[ \text{PPI} = \frac{\sqrt{W^2 + H^2}}{D} \]

Pixel Density (PPI):

Unit Converter ▲

Unit Converter ▼

From:	To:

1. What is a Pixel Density Calculator?

Definition: This calculator determines the pixel density (PPI - pixels per inch) of a display based on its resolution and screen size.

Purpose: It helps compare display sharpness and understand how densely packed the pixels are on a screen.

2. How Does the Calculator Work?

The calculator uses the formula:

\[ \text{PPI} = \frac{\sqrt{W^2 + H^2}}{D} \]

Where:

\( \text{PPI} \) — Pixels per inch (pixel density)
\( W \) — Width in pixels
\( H \) — Height in pixels
\( D \) — Diagonal screen size in inches

Explanation: The formula calculates the diagonal resolution in pixels and divides it by the physical screen size to determine how many pixels fit in one inch.

3. Importance of Pixel Density

Details: Higher PPI means sharper images and text. PPI affects perceived image quality, viewing distance, and readability.

4. Using the Calculator

Tips: Enter the screen resolution (width and height in pixels) and the diagonal screen size in inches. All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What's a good PPI for a smartphone?
A: Modern smartphones typically have 300-500 PPI. 300+ PPI is considered "retina" quality at normal viewing distances.

Q2: How does PPI differ from DPI?
A: PPI refers to screen pixels, while DPI (dots per inch) refers to printer resolution. They're often used interchangeably but technically different.

Q3: Does higher PPI always mean better quality?
A: While higher PPI generally means sharper display, factors like color accuracy, contrast, and viewing distance also affect perceived quality.

Q4: What's the PPI of a 4K 27-inch monitor?
A: A 3840×2160 (4K) 27" monitor has about 163 PPI (you can calculate this with our tool).

Q5: How does viewing distance affect PPI perception?
A: At greater distances, lower PPI displays can appear as sharp as higher PPI displays viewed up close.