1. What is PPI?

PPI (Pixels Per Inch) is a measurement of pixel density that indicates how many pixels are displayed per inch on a digital screen. It's an important factor in determining the sharpness and clarity of a display.

2. How Does the Calculator Work?

The calculator uses the PPI formula:

Where:

• \( width \) — Screen width in pixels
• \( height \) — Screen height in pixels
• \( diagonal \) — Screen diagonal size in inches

Explanation: The formula calculates the diagonal resolution in pixels (using the Pythagorean theorem) and divides it by the physical diagonal size of the screen in inches.

3. Importance of PPI Calculation

Details: PPI helps determine display quality. Higher PPI means sharper images and text. It's crucial for graphic designers, photographers, and anyone concerned with display quality.

4. Using the Calculator

Tips: Enter the screen resolution (width and height in pixels) and the physical diagonal size of the screen in inches. All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between PPI and DPI?
A: PPI refers to pixel density on screens, while DPI (dots per inch) refers to printer resolution. Though often used interchangeably, they're technically different.

Q2: What is a good PPI for a smartphone?
A: Modern smartphones typically have 300-500 PPI. The human eye can't distinguish individual pixels above about 300 PPI at normal viewing distances.

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

Q4: How does PPI relate to Retina displays?
A: Apple's Retina displays have high enough PPI that pixels are indiscernible at normal viewing distances (typically over 300 PPI).

Q5: Can I calculate PPI for a rectangular screen?
A: Yes, this calculator works for any rectangular screen regardless of aspect ratio.