PPI Calculator
Calculate pixels per inch for any display. Essential for understanding display sharpness and quality.
Result
- PPI
- -
- Total Pixels
- -
Conversion Guide
Conversion
D
Diagonal Pixels
Diagonal = √(Width² + Height²)
Calculate diagonal pixel count using Pythagorean theorem
P
PPI
PPI = Diagonal Pixels ÷ Diagonal (inches)
Divide diagonal pixels by screen diagonal size
Step-by-Step Scenario
Example Scenario
Resolution
1920×1080
Diagonal
24 inches
1
Calculate Diagonal Pixels
- √(1920² + 1080²) = √(3,686,400 + 1,166,400)
- = √4,852,800 = 2,203 pixels
Use Pythagorean theorem to find diagonal pixel count
2
Calculate PPI
- PPI = 2,203 ÷ 24
Additional Examples
4K Monitor
Resolution: 3840×2160
Size: 27 inches
PPI
≈163 PPI
Smartphone
Resolution: 1080×1920
Size: 5.5 inches
PPI
≈401 PPI
Characteristics of PPI
Display Sharpness
Higher PPI means sharper display. Retina displays (220+ PPI) provide crisp text and images.
Device Comparison
Compare PPI across different devices. Smartphones typically have 300-500+ PPI, monitors 90-150 PPI.
Viewing Distance
PPI requirements vary by viewing distance. Closer viewing (phones) needs higher PPI than distant viewing (TVs).
Quality Indicator
PPI is a key indicator of display quality. Higher PPI generally means better image sharpness and clarity.
Important Notes
- PPI (Pixels Per Inch) measures display sharpness. It's calculated by dividing diagonal pixel count by diagonal screen size in inches.
- Higher PPI means sharper display, but may require more processing power and can make UI elements appear smaller.
- Viewing distance matters: phones need 300+ PPI (viewed close), TVs need 40-100 PPI (viewed far), monitors need 90-150 PPI.
- Retina displays are typically 220+ PPI, where individual pixels are not visible at normal viewing distance.
- For web development, consider PPI when designing responsive layouts. Higher PPI displays may need different image resolutions.
Frequently Asked Questions
Find answers to common questions about PPI calculation.