27" QHD vs 27" 4K

Same screen area, different pixel math: the 27-inch 4K has 163 PPI against 109 on the 27-inch 1440p.

Dimensions and density

	27" QHD	27" 4K
Resolution	2560 × 1440	3840 × 2160
Width	23.5 in (59.8 cm)	23.5 in (59.8 cm)
Height	13.2 in (33.6 cm)	13.2 in (33.6 cm)
Screen area	312 in²	312 in² (same)
Pixel density	109 PPI	163 PPI
Pixel pitch	0.233 mm	0.156 mm
60 PPD distance	31.6 in (80.3 cm)	21.1 in (53.5 cm)

The 27-inch 4K is the clearly sharper panel at 163 PPI (pixel pitch 0.156 mm). Past roughly 140 PPI you will want OS scaling; around 110 PPI works unscaled. Enter your own viewing distance in the calculator to see pixels per degree, the measure that decides what your eyes actually resolve.

Desk distance

The 27-inch 1440p reaches the 60 central pixels-per-degree reference at 31.6 in (80.3 cm) and the 27-inch 4K at 21.1 in (53.5 cm). Use the PPD calculator to compare angular pixel density at your own distance. These reference distances do not guarantee that pixels or resolution differences become invisible.

Decided? See current prices for 27-inch 1440p and 27-inch 4K monitors on Amazon.

Open this comparison in the calculator, drawn to scale

Reading this on an iPhone? Open it in the calculator and tap "Setup on your wall" to see the screens in your room at true physical size, in augmented reality.

Common questions

Is a 27-inch 4K monitor better than a 27-inch 1440p?

For screen space: both have the same screen area. For sharpness: 163 PPI against 109. Which wins depends on your distance and use; the numbers above make the trade-off concrete.

What is the PPI of a 27-inch 4K monitor?

3840 by 2160 pixels across a 27-inch diagonal gives 163 pixels per inch, a pixel pitch of 0.156 mm.

How these measurements are calculated

For a diagonal d and aspect ratio w:h, screen width is d × w / √(w² + h²), and height is d × h / √(w² + h²). Area is width × height; PPI is √(horizontal pixels² + vertical pixels²) / diagonal in inches. Results are rounded for display.

Screen dimensions exclude the frame, feet and stand. Check the manufacturer's measurements for furniture and mounting clearance. A flat-screen viewing angle is 2 × atan(width / (2 × eye-to-screen distance)). The 40° cinema target is a preference, not a requirement; adjust the viewing angle for your room. It is approximately equivalent, for a 16:9 screen, to the distance × 0.835 sizing rule in the THX viewing guide.

The 60 central pixels-per-degree reference is a rule of thumb, not a guarantee that two displays look identical. Eyesight, contrast, source quality and panel technology also matter. Check sharpness at your own viewing distance.

Every number on this page is computed from resolution and diagonal with the DisplayMath screen size calculator. Free, no signup, runs in your browser. Content updated 2026-09-09. Feedback? Email hello@displaymath.com or find us on Instagram. About · Privacy and affiliate disclosure. © 2026 DisplayMath. All rights reserved.