1. What is PPI (Pixels Per Inch)?

Definition: PPI measures the pixel density of a digital image or display, indicating how many pixels are packed into one linear inch.

Purpose: It helps determine image quality and sharpness, especially important for printing and display devices.

2. How Does the PPI Calculator Work?

The calculator uses the formula:

Where:

• \( \text{PPI} \) — Pixel density (pixels per inch)
• \( \text{Width} \) — Horizontal resolution in pixels
• \( \text{Height} \) — Vertical resolution in pixels
• \( \text{Diagonal} \) — Screen size in inches (measured diagonally)

Explanation: The formula calculates the diagonal resolution in pixels and divides it by the physical diagonal size in inches.

3. Importance of PPI Calculation

Details: Higher PPI means sharper images. Understanding PPI helps in choosing appropriate image resolutions for different media (web, print, displays).

4. Using the Calculator

Tips: Enter the image/display width and height in pixels, and the diagonal size in inches. All values must be > 0.

5. Frequently Asked Questions (FAQ)

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

Q2: What's a good PPI for printing?
A: For high-quality prints, 300 PPI is standard. For large format prints viewed from a distance, 150-200 PPI may suffice.

Q3: How does PPI affect image quality?
A: Higher PPI means more pixels per inch, resulting in sharper, more detailed images when viewed at the same size.

Q4: Can I calculate PPI without knowing the diagonal size?
A: No, you need all three values (width, height, and diagonal) to calculate PPI accurately.

Q5: Does PPI affect file size?
A: Indirectly - higher resolution images (more pixels) typically have higher PPI when printed at smaller sizes, and these files are larger.