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40-inch 5K2K monitor PPI: density and Retina distance

By TechCompare · Updated · How we check

At 40 inches (101.6 cm), 5120 × 2160 works out to 139 PPI, and single pixels stop being visible at 25 inches (63 cm) away. That's less dense than the 34-inch 5K2K.

Same 1.57 × 0.79 in (40 × 20 mm) of Screen, at Real Pixel Density

This simulation shows an identical 1.57 × 0.79 in (40 × 20 mm) physical patch magnified at native pixel resolution. It demonstrates how typography and curves render across different screen densities.

Standard 24-inch 1080p92 PPI · 145×72 px

Standard desktop baseline with noticeable pixel staircasing on fine text.

40" 5K2K ultrawide139 PPI · 219×109 px

Very sharp text with smooth curves. Pixels blend together with no visible steps.

Diagonal physical size: 40 inches (101.6 cm)
Native resolution: 5120 × 2160
This exact 5120×2160 at 40″ panel, pre-loaded. Compare another size or try a second panel.
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A 40-inch 5K2K monitor spreads 5120 × 2160 pixels over 573 square inches (3697 cm²), which works out to 138.92 PPI. It uses the 5120 × 2160 grid of the 34-inch 5K2K, with 11,059,200 pixels in total. Spread over the larger screen, the density falls below the 34-inch version at 163 PPI.

Pixel density
138.92 PPI
5120×2160 at 40″
Retina distance
25 in (63 cm)

Recommended monitors

Based on the specs on this page, here are the monitors TechCompare recommends.

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How this is calculated

Retina distance is 25 inches (63 cm), and the pixel grid only shows inside that distance. The screen measures 36.9 inches (93.6 cm) wide and 15.5 inches (39.5 cm) tall. LG's Canadian business page for the 40U990A-W lists the panel at 39.7 inches (100.8 cm), with a 5120 × 2160 grid, a 2500R curve and a 120 Hz maximum refresh rate. The model name rounds up to 40, and this page works from 40 inches (101.6 cm), so at LG's listed size the same pixels give 139.97 PPI, against 138.92 here.

Verdict

Choose a 40-inch 5K2K when you want the 5120 × 2160 grid on a bigger desk footprint and can accept lower density than the 34-inch panel. The screen measures 36.9 inches (93.6 cm) wide and 15.5 inches (39.5 cm) tall, and its Retina distance is 25 inches (63 cm). Text is a little softer than on the 34-inch version, so the extra width comes at the cost of fine detail.

More Monitors scenarios

24" 1080p monitor
A 24-inch 1080p monitor works out to 91.79 PPI, the baseline pixel density most people grew up with and the point where standard sub-pixel font rendering still looks crisp at a typical desk distance.
View details
24" 1440p monitor
A 24-inch 1440p monitor delivers 122.38 PPI, a high density for a desktop panel.
View details
27" 1080p monitor
A 27-inch 1080p monitor works out to 81.59 PPI, a low pixel density that gives the same 1920×1080 grid larger physical pixels than on a smaller panel.
View details

Related guides

38" ultrawide screen size
The nearest ultrawide size page, for a rough desk check.
View guide
4K vs 5K2K
5120 × 2160 against 3840 × 2160, with pixel density and the wider canvas.
View guide
5K2K at 165 Hz bandwidth
The link speed 5K2K needs at 165 Hz, with DSC notes.
View guide

Frequently asked questions

Is a 40-inch 5K2K monitor sharp enough for text?
At 139 PPI, single pixels stop being visible at 25 inches (63 cm) away. Inside that distance you may see faint pixel structure on high-contrast text, so the answer depends on how close you sit.
Is the diagonal of a 40-inch 5K2K monitor exact?
Close to it. LG's spec table lists 39.7 inches (100.8 cm) for this panel, while the model number says 40. That small gap changes the PPI only slightly.
How many pixels does a 40-inch 5K2K monitor have?
11,059,200 pixels in total, or 11.06 million. The 34-inch 5K2K uses the same grid, so the total is the same.

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