What is UHD resolution?

UHD (Ultra High Definition) is 3840x2160 pixels — exactly four times the pixel count of Full HD (1920x1080). It uses a 16:9 aspect ratio and contains about 8.3 megapixels per frame.

Is UHD the same as 4K?

In consumer contexts, yes — "4K" and "UHD" both refer to 3840x2160. True cinema 4K (DCI 4K) is slightly wider at 4096x2160, but UHD is the standard used in TVs, monitors, and streaming platforms.

What PPI is considered sharp for a monitor?

Most people cannot distinguish individual pixels above roughly 90–110 PPI at a normal viewing distance of 50–75 cm. Apple's "Retina" displays target 220+ PPI for close viewing on phones and laptops.

How many megapixels is UHD?

3840 × 2160 = 8,294,400 pixels, which rounds to approximately 8.3 megapixels per frame.

Does UHD require a special HDMI cable?

Yes. Full 4K at 60 Hz requires HDMI 2.0 or higher (18 Gbps bandwidth). HDMI 2.1 is needed for 4K at 120 Hz or 8K content.

How much larger is UHD than 1080p?

UHD has exactly 4× the pixels of 1080p (8,294,400 vs 2,073,600 pixels). Each axis is doubled: 1920→3840 and 1080→2160.

UHD Resolution Reference

Name: UHD Resolution Reference
Availability: InStock
Author: Nham Vu

Look up UHD/4K resolution specs, calculate pixel density for any screen size, and compare resolutions side by side.

Pixel Density Calculator

Screen Diagonal (inches)

Resolution

UHD / 4K Spec Sheet

Standard name: Ultra High Definition (UHD)
Resolution: 3840 × 2160
Aspect ratio: 16:9
Total pixels: 8,294,400
Megapixels: ~8.3 MP
vs. 1080p (pixel count): 4× more pixels
Common frame rates: 24, 30, 60, 120 Hz
HDMI requirement: HDMI 2.0+ (60 Hz)
Display Port requirement: DP 1.4 (60 Hz)

Resolution Comparison

Sorted by pixel count, highest first

Name	Resolution	Megapixels	vs UHD

Aspect Ratio: 16:9

UHD uses the same 16:9 widescreen aspect ratio as 1080p and 720p, making it fully compatible with modern TVs, monitors, and streaming platforms without letterboxing or pillarboxing.

720p 1280×720

1080p 1920×1080

1440p 2560×1440

UHD 4K 3840×2160

Rectangles above are proportional to pixel area (not screen size).

Summary

Look up UHD/4K resolution specs, calculate pixel density for any screen size, and compare resolutions side by side.

How it works

Browse the resolution comparison table to see how UHD stacks up against other standards.
Enter your screen diagonal (in inches) in the PPI calculator to get the exact pixel density.
Review the aspect ratio and total pixel count breakdowns in the spec cards.
Use the resolution selector to calculate PPI for any listed resolution at your screen size.

Use cases

Verify whether a display purchase meets UHD spec.
Calculate the pixel density of a monitor or TV at a given screen size.
Understand the pixel count difference between 1080p, 1440p, 4K, and 8K.
Confirm aspect ratio and total megapixel count for video production work.
Choose the right export resolution for streaming or video editing projects.
Compare display sharpness between laptop, desktop, and TV screen sizes.

Frequently Asked Questions

Last updated: 2026-06-11 · Reviewed by Nham Vu