Display & DPI Scaling Calculator
Calculate effective logical viewport dimensions, UI pixel density, and detect fractional scaling blur issues across Windows 11 and macOS.
Workspace size reported to web browser.
Perceived text & element scale.
Interpolated sub-pixel rendering.
What is Display DPI Scaling (Integer vs Fractional)?
DPI scaling is an operating system rendering feature that enlarges user interface elements and text on high-density screens by translating logical CSS pixels to physical display pixels via integer or fractional multipliers.
Integer vs. Fractional Scaling Breakdown
| Scaling % | Ratio | Scaling Type | Clarity & Performance |
|---|---|---|---|
| 100% | 1.0x | Integer (Native) | 100% Sharp | Zero Overhead |
| 125% | 1.25x | Fractional | Minor Text Interpolation Blur |
| 150% | 1.50x | Fractional | Standard 4K Desktop Setting |
| 200% | 2.0x | Integer (Retina) | Pixel Perfect 4-to-1 Mapping |
Frequently Asked Questions
Why does 150% scaling make text blurry on Windows or Mac? ↓
Fractional scaling (like 125% or 150%) forces the OS to map non-integer pixel ratios. On macOS, it renders UI at double resolution (5K) and scales down, causing slight blurriness and GPU overhead. On Windows, legacy desktop apps fail subpixel font anti-aliasing.
What is the difference between logical viewport and physical resolution? ↓
Physical resolution is the actual number of hardware LED pixels on your monitor (e.g. 3840×2160). Logical viewport is the size reported to browsers and software after applying OS DPI scaling (e.g. 2560×1440 at 150% scaling).
What is integer scaling vs. fractional scaling? ↓
Integer scaling uses exact whole-number multipliers like 100% (1x) or 200% (2x Retina), where 1 logical pixel maps to exactly 4 physical hardware pixels. Fractional scaling uses decimal multipliers like 125% or 150%, requiring interpolation that reduces text sharpness.
What is the best scaling setting for a 27-inch 4K monitor? ↓
For a 27-inch 4K monitor (163 PPI), 150% scaling provides the standard 2560×1440 logical workspace with comfortable UI sizing. For absolute 2x Retina sharpness, 200% scaling provides a 1920×1080 logical workspace.
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