Your Screen Information
Calibrate for Accurate DPI
For the most accurate results, calibrate your screen using a credit card or enter your monitor's diagonal size.
Adjust the slider until the blue rectangle matches the width of a real credit card on your screen.
Enter your monitor's diagonal size (usually found in product specifications).
How to Use This Tool
- Automatic Detection: Your screen resolution and device information are detected automatically when you load this page.
- Choose Calibration Method: Select either credit card calibration (most accurate) or manual entry if you know your monitor's size.
- Calibrate: If using credit card method, adjust the slider until the blue rectangle matches your physical credit card width. If using manual entry, input your screen's diagonal measurement.
- View Results: Click the button to calculate your screen's DPI, physical dimensions, and other specifications.
Why Screen DPI Matters
For Designers
Understanding your screen's DPI helps you create pixel-perfect mockups and accurately preview how designs will look on different devices. A 27-inch 4K monitor has very different pixel density than a laptop screen.
For Developers
Knowing your display's DPI is crucial for responsive design testing, understanding device pixel ratio, and ensuring images and UI elements scale correctly across different screen densities.
For Print Professionals
Screen DPI differs significantly from print DPI (typically 300). Understanding your monitor's pixel density helps you better judge how digital assets will translate to physical prints.
Understanding Your Results
What is DPI vs. PPI?
DPI (Dots Per Inch) and PPI (Pixels Per Inch) are often used interchangeably for screens, though technically DPI refers to print resolution. For digital displays, PPI is the accurate term, measuring how many pixels fit into one linear inch of screen space.
Pixel Density Classifications
| DPI Range | Classification | Typical Devices |
|---|---|---|
| Below 100 | Low Density | Older desktop monitors, budget displays |
| 100-150 | Standard Desktop | Most 1080p and 1440p monitors |
| 150-220 | High Density | 4K monitors, high-end laptops |
| 220+ | Retina/HiDPI | MacBook Pro, 4K laptops, mobile devices |
Common Screen Sizes and DPI
- 24" 1080p Monitor: ~92 DPI (Standard Desktop)
- 27" 1440p Monitor: ~109 DPI (Standard Desktop)
- 27" 4K Monitor: ~163 DPI (High Density)
- 15" MacBook Pro: ~220 DPI (Retina Display)
- 13" Laptop (1080p): ~170 DPI (High Density)
- 32" 4K Monitor: ~138 DPI (High Density)
Frequently Asked Questions
What's a good DPI for design work?
For professional design work, a DPI between 100-163 is ideal. Many designers prefer 27-inch 4K monitors (163 DPI) as they provide excellent clarity while still allowing comfortable viewing distances. Ultra-high DPI displays (220+) can sometimes make UI elements too small without scaling.
Why does my operating system report a different DPI?
Operating systems often use logical DPI (usually 96 or 72) for compatibility reasons, not your actual physical DPI. Windows and macOS apply scaling factors to make content readable. This tool calculates your true physical pixel density based on screen size and resolution.
Does higher DPI always mean better quality?
Not necessarily. While higher DPI provides sharper images, it also requires more GPU power and can make UI elements tiny without scaling. For desktop work, 109-163 DPI is often the sweet spot. Beyond 220 DPI, you'll likely need OS scaling, which can cause compatibility issues with some applications.
How do I measure my screen manually?
Use a ruler or measuring tape to measure the diagonal distance of your screen's visible display area (corner to corner), excluding the bezel. Most manufacturers list this measurement in product specifications. For accuracy, measure in centimeters and convert to inches (divide by 2.54).
What is device pixel ratio?
Device pixel ratio (DPR) is the ratio between physical pixels and logical pixels. A DPR of 2 means the device uses 2x2 (4) physical pixels to display one logical pixel. Retina displays typically have DPR of 2 or higher, making images and text appear smoother.
Can I use this tool on mobile devices?
Yes, this tool works on smartphones and tablets. However, the credit card calibration method works best on desktop monitors. For mobile devices, you can use manual entry if you know your device's screen size from manufacturer specifications.
Why is my screen's DPI different from 96 or 72?
The values 96 DPI (Windows) and 72 DPI (older Mac) are legacy reference values, not actual physical measurements. Modern displays have widely varying pixel densities. A 4K monitor has much higher DPI than a 1080p monitor of the same physical size.
How accurate is the credit card calibration method?
Very accurate when done carefully. Credit cards follow the ISO/IEC 7810 ID-1 standard (85.60 × 53.98 mm). As long as you precisely match the on-screen rectangle to your physical card, this method can achieve accuracy within 1-2 DPI of your actual screen density.
What if my browser zoom is not at 100%?
Browser zoom will affect the calibration accuracy. For best results, ensure your browser zoom is set to 100% (press Ctrl+0 or Cmd+0). This tool attempts to account for zoom levels, but manual calibration works best at default zoom.
Do I need to calibrate every time I visit?
No, once you know your screen's DPI, it remains constant unless you change monitors or resolution. You can bookmark your results or make a note of your DPI value. The physical properties of your display don't change between visits.
Recommended Monitors for Design & Development
For accurate color work and comfortable long-term use, these monitors are trusted by professionals:
Dell UltraSharp 27" 4K (U2723DE)
Resolution: 3840 × 2160
Color: 99% sRGB, 95% DCI-P3
Excellent for UI design and development. Built-in USB-C hub, height-adjustable stand, and factory color calibration make this a top choice for professionals.
Check Price on Amazon →LG UltraFine 27" 5K Display
Resolution: 5120 × 2880
Color: P3 Wide Color Gamut
Retina-level pixel density for razor-sharp text and graphics. Ideal for graphic designers and photographers who need exceptional detail and color accuracy.
Check Price on Amazon →BenQ 32" 4K Designer Monitor (PD3220U)
Resolution: 3840 × 2160
Color: 100% sRGB, Rec.709
Larger screen with comfortable pixel density. AQCOLOR technology ensures consistent color accuracy, perfect for CAD/CAM and creative professionals needing screen real estate.
Check Price on Amazon →Affiliate Disclaimer: We may earn a commission from qualifying purchases made through links on this page at no additional cost to you. We only recommend products we believe will be valuable to our users. This helps support the maintenance of this free tool.