Pixels Per Inch Calculator

PPI Formula:

\[ PPI = \frac{\sqrt{h^2 + v^2}}{diagonal} \]

Pixels Per Inch (PPI):

Unit Converter ▲

Unit Converter ▼

From:	To:

1. What is Pixels Per Inch?

Pixels Per Inch (PPI) is a measurement of the pixel density of electronic image devices like computer monitors, smartphones, and television screens. It represents the number of individual pixels that can be placed in a line within the span of one inch.

2. How Does the Calculator Work?

The calculator uses the PPI formula:

\[ PPI = \frac{\sqrt{h^2 + v^2}}{diagonal} \]

Where:

\( h \) — Horizontal resolution in pixels
\( v \) — Vertical resolution in pixels
\( diagonal \) — Screen diagonal size in inches

Explanation: The formula calculates the diagonal pixel count using the Pythagorean theorem and divides it by the physical diagonal size to determine pixel density.

3. Importance of PPI Calculation

Details: PPI is crucial for understanding image quality and sharpness. Higher PPI values generally mean sharper, more detailed images since pixels are packed more densely on the display surface.

4. Using the Calculator

Tips: Enter horizontal and vertical pixel counts (must be positive integers) and the diagonal screen size in inches (must be positive decimal). All values are required for calculation.

5. Frequently Asked Questions (FAQ)

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

Q2: What is considered a good PPI value?
A: For smartphones, 300+ PPI is good; for computer monitors, 100-140 PPI is typical; for TVs, 50-100 PPI is common depending on viewing distance.

Q3: Does higher PPI always mean better quality?
A: Higher PPI generally means sharper images, but beyond a certain point (depending on viewing distance and human visual acuity), the difference becomes imperceptible.

Q4: How does PPI affect image scaling?
A: Higher PPI displays can show more detail without scaling, while lower PPI displays may require image scaling which can reduce quality.

Q5: Can I calculate PPI for printed images?
A: This calculator is designed for digital displays. For printed materials, DPI calculations consider different factors like printer capabilities and paper quality.