PPI Calculator – Pixels Per Inch Screen Density Calculator
Calculate screen pixel density (PPI) from resolution and size
Table of Contents
How to Use
- Enter the screen width in pixels
- Enter the screen height in pixels
- Enter the diagonal screen size in inches
- Click calculate to see the PPI and screen details
What is PPI?
PPI (Pixels Per Inch) is a measurement of pixel density that indicates how many pixels fit into one linear inch of a display. Higher PPI means more pixels are packed into the same space, resulting in sharper, clearer images and text.
PPI is calculated by dividing the diagonal screen resolution (in pixels) by the diagonal screen size (in inches). The formula uses the Pythagorean theorem to find the diagonal pixel count: √(width² + height²).
PPI Categories and Quality
| PPI Range | Category | Quality |
|---|---|---|
| < 100 | Low | Visible pixels, poor for close viewing |
| 100 - 150 | Standard | Acceptable for most desktop monitors |
| 150 - 200 | Good | Sharp text, comfortable for extended use |
| 200 - 300 | High | Very sharp, excellent for design work |
| > 300 | Retina | Apple's Retina standard, exceptional clarity |
Common Device PPI Values
- Desktop Monitors (24" 1080p): ~92 PPI
- Desktop Monitors (27" 1440p): ~109 PPI
- Desktop Monitors (27" 4K): ~163 PPI
- MacBook Pro 13" (2020+): ~227 PPI
- iPad Pro 12.9": ~264 PPI
- iPhone 13: ~460 PPI
- Samsung Galaxy S21: ~421 PPI
PPI vs DPI
PPI (Pixels Per Inch) refers to digital screens and displays, while DPI (Dots Per Inch) refers to printed materials and printers. Though often used interchangeably, they measure different things:
- PPI - Digital displays: pixels arranged in a grid on screens
- DPI - Print resolution: ink dots printed on paper
- For screens, always use PPI for accurate measurements
- High PPI doesn't directly translate to high DPI printing quality
Why PPI Matters
- Choosing monitors - Higher PPI means sharper text and images
- Graphic design - Ensures designs appear as intended on different screens
- Photography - Helps evaluate display quality for image editing
- Gaming - Balance between PPI and performance (GPU load)
- Reading and productivity - Higher PPI reduces eye strain
- Mobile devices - Closer viewing distance requires higher PPI
Frequently Asked Questions
- What is a good PPI for a monitor?
- For desktop monitors viewed at arm's length, 90-110 PPI is standard. For closer viewing or design work, 150-200 PPI is ideal. Above 200 PPI provides exceptional clarity but may require UI scaling.
- Does higher PPI always mean better?
- Not necessarily. While higher PPI provides sharper images, it also requires more powerful graphics hardware and may need UI scaling. The ideal PPI depends on viewing distance and use case.
- How do I find my screen's resolution?
- On Windows: Right-click desktop → Display settings. On Mac: Apple menu → System Settings → Displays. On mobile: Check device specifications online.
- Why is my high-resolution monitor's PPI lower than my phone's?
- Viewing distance matters. Phones are held 10-12 inches from your eyes and need 300+ PPI. Monitors viewed at 20-30 inches need only 90-150 PPI to look equally sharp.
- What's the difference between resolution and PPI?
- Resolution is the total number of pixels (e.g., 1920×1080). PPI is pixel density - how tightly those pixels are packed. A 24" and 32" monitor with 1080p resolution have the same resolution but different PPI.