What Is 4K Resolution?
4K resolution refers to a display with a horizontal pixel count of roughly 4,000 pixels. On consumer TVs, monitors, laptops, and phones, 4K almost always means 3840×2160 pixels — also called UHD (Ultra High Definition). That is exactly four times the pixels of a 1080p Full HD screen.
Key 4K specs
- • Resolution: 3840 × 2160 pixels
- • Aspect ratio: 16:9
- • Total pixels: 8,294,400 (~8.3 megapixels)
- • Common labels: UHD, 4K UHD, 2160p
4K PPI on common screen sizes
| Diagonal | PPI at 4K | Typical use |
|---|---|---|
| 15.6″ | ~282 | Laptop |
| 27″ | ~163 | Monitor |
| 32″ | ~138 | Large monitor |
| 55″ | ~80 | TV |
| 65″ | ~68 | TV |
4K vs 1080p vs 1440p
1080p (Full HD) is 1920×1080 — about 2.1 MP. 1440p (QHD) is 2560×1440 — about 3.7 MP. 4K UHD (3840×2160) packs 8.3 MP, giving four times the detail of 1080p at the same screen size.
How to check if your screen is 4K
Open our screen resolution detector — if the headline shows 3840×2160 (or 2160 height with a 16:9 aspect), your display is running at native 4K. See also our resolutions guide and step-by-step instructions.