Screen PPI Calculator
Find the pixel density of any screen from its resolution and size
Screen Resolution
Diagonal Screen Size
Common Device Presets
Pixel Density Reference
| PPI Range | Category | Typical Devices |
|---|---|---|
| < 100 | Low density | Large 1080p TVs, older monitors |
| 100 – 150 | Standard | 24" 1080p, 27" 1440p, 32" 4K monitors |
| 150 – 220 | High | 27" 4K monitors, older laptops |
| 220 – 320 | Retina / HiDPI | MacBook displays, iPads, premium laptops |
| > 320 | Ultra HiDPI | Modern smartphones, premium tablets |
About the Screen PPI Calculator
The Screen PPI Calculator measures the pixel density of any display from its resolution and diagonal size. PPI (pixels per inch) describes how tightly packed the pixels are — higher PPI means sharper text, smoother edges, and less visible "pixelation" at normal viewing distance.
- Calculate PPI from any width × height resolution and screen size
- Supports both inches and centimetres for the diagonal length
- Shows dot pitch in millimetres and micrometres (µm)
- Includes physical width/height, aspect ratio, and total pixel count
- Presets for iPhone, iPad, MacBook, 4K monitors, ultrawides, and TVs
- Density category labels (Standard, High, Retina, Ultra HiDPI) for quick interpretation
- Runs entirely in your browser — nothing is uploaded
How to Use the Screen PPI Calculator
- 1
Enter the screen resolution
Type the horizontal and vertical pixel counts. For example, a 4K monitor is 3840 × 2160, and a Full HD display is 1920 × 1080. Use the screen's native resolution, not a scaled or rendered one.
- 2
Enter the diagonal size
Type the diagonal length of the panel — this is the number manufacturers advertise (e.g., "27-inch monitor" or "6.1-inch phone"). Switch between inches and centimetres with the unit toggle.
- 3
Read the result
The calculator updates live as you type. The big number is the PPI, with a density category (Standard, Retina, etc.) shown below. Additional cards show aspect ratio, total pixels, dot pitch, and the physical width × height.
- 4
Compare with a preset (optional)
Click any preset (iPhone 15 Pro, 27" 4K monitor, 55" 4K TV, etc.) to instantly load common configurations and compare them against your screen.
Tip: If your laptop reports a "scaled" resolution in Display settings, find the native panel resolution in the spec sheet — that's what determines actual PPI.
Common Use Cases
Buying a New Monitor
- • Compare PPI between 27" 1440p and 32" 4K options
- • Decide whether you need HiDPI scaling on a 4K panel
- • Check if text will look sharp at your viewing distance
Choosing a Phone or Tablet
- • Compare iPhone, iPad, and Android device pixel densities
- • See whether a budget tablet matches a flagship in sharpness
- • Verify a refurbished device matches advertised specs
UI and App Design
- • Decide between @1x, @2x, and @3x asset exports
- • Calculate physical mm size of a UI element on real hardware
- • Pick a target PPI for design mockups and Figma frames
Photo & Print Workflow
- • Confirm that print resolution exceeds the monitor's PPI
- • Match preview size on screen to the final printed size
- • Compare paper DPI vs. screen PPI when proofing
Gaming Setups
- • Evaluate ultrawide vs. dual-monitor configurations
- • Choose between high-refresh 1440p and slower 4K screens
- • Plan GPU load by checking total pixels to render
Living Room TVs
- • Decide if upgrading from 1080p to 4K is worth it at your distance
- • Compare 55", 65", and 75" 4K TVs for sharpness
- • Find the seating distance where 4K pixels become invisible
Frequently Asked Questions
What is PPI?
PPI stands for "pixels per inch" — the number of individual pixels packed into each linear inch of a screen. Higher PPI means smaller, denser pixels and a sharper image. Phones typically have 300–500+ PPI, laptops 150–250, and desktop monitors 90–160.
What formula does the calculator use?
PPI is calculated as the diagonal in pixels divided by the diagonal in inches: PPI = √(width² + height²) ÷ diagonal_inches. The width and height in this formula are in pixels.
Is PPI the same as DPI?
In everyday language they're often used interchangeably, but technically PPI applies to screens (pixels) and DPI to print (dots of ink). A printer can lay down many dots to render a single image pixel, so a 600 DPI printer is not directly comparable to a 600 PPI screen.
What counts as a "Retina" display?
Apple introduced "Retina" to describe displays where, at the typical viewing distance, individual pixels are too small to be seen by a normal eye. The threshold is roughly 220 PPI for laptops at arm's length and around 300 PPI for phones held closer to the face.
Does a higher PPI always look better?
Up to a point. Once pixels become smaller than the eye can resolve at the viewing distance, extra PPI is wasted. A 1080p 55" TV looks pixelated at 1 metre away but perfectly fine from 3 metres — viewing distance matters as much as PPI.
What is dot pitch?
Dot pitch is the physical distance between adjacent pixels, usually measured in millimetres. It's the inverse of PPI: smaller dot pitch means higher density. A typical monitor might have a 0.26 mm dot pitch, while a high-end phone is closer to 0.05 mm.
Why does the screen size include the bezel sometimes?
It shouldn't. Manufacturers measure the diagonal of the active display area, not the outer chassis. If you measure yourself, place the tape from one inside corner of the panel to the diagonally opposite inside corner — ignoring any bezel.
What does the dot pitch in micrometres mean?
One micrometre (µm) is 0.001 mm. Spec sheets sometimes list pixel pitch in µm — particularly for OLED phones and AR/VR displays where pitch is well below 0.1 mm. A 300 PPI display has a pitch around 85 µm; a 500 PPI phone is closer to 50 µm.
Is my data safe? Does this tool send data to a server?
No data leaves your browser. All calculations happen entirely client-side using JavaScript. The numbers you enter are never uploaded or stored anywhere.