Size difference
The 40″ ultrawide 5K2K has 12% more screen area than the 38″ ultrawide, and is 1.8″ wider and 0.9″ taller. The 38″ ultrawide measures 35.1″ × 14.6″ (89 × 37 cm) with a 21:9 aspect ratio. The 40″ ultrawide 5K2K measures 36.9″ × 15.5″ (94 × 39 cm) at 21:9. Panel sizes exclude bezels and stands, so allow about 1–3 cm extra on each side.
Sharpness and pixel density
The 40″ ultrawide 5K2K is sharper at 139 PPI versus 109 PPI on the 38″ ultrawide, a 27% increase in pixel density. Individual pixels stop being visible to 20/20 vision beyond about 31″ (80 cm) on the 38″ ultrawide and 25″ (63 cm) on the 40″ ultrawide 5K2K.
Workspace
The 40″ ultrawide 5K2K has 80% more pixels (11.1 vs 6.1 MP). That only becomes extra workspace if the UI scale lets you use it: on a Mac, the recommended modes look like 3840 × 1600 on the 38″ ultrawide and 4011 × 1692 on the 40″ ultrawide 5K2K.
On a Mac
The 38″ ultrawide: sharp, not Retina. It runs at native 3840 × 1600, with a comfortable UI size and clean pixel mapping. Text is sharp, but you may notice individual pixels up close. The 40″ ultrawide 5K2K: scaled, mostly fine. It works best scaled to look like 4011 × 1692. macOS renders 8022 × 3384 and resamples it, so text is slightly soft, which most people find acceptable.
Why this matters: macOS draws its interface at exactly 1× or 2×, so displays near 110 or 220 PPI look best. Read the Mac monitor guide or how we rate sharpness.
Desk and viewing distance
For comfortable viewing, sit roughly 38″ (95 cm) from the 38″ ultrawide and 40″ (102 cm) from the 40″ ultrawide 5K2K. A desk at least 86 cm deep keeps the larger screen from feeling too close.
Which should you choose?
38″ ultrawide
Choose the 38″ ultrawide if your desk is shallow or narrow, you game and want higher frame rates from the same GPU, or you use a Mac.
40″ ultrawide 5K2K
Choose the 40″ ultrawide 5K2K if you want a bigger, more immersive screen or sharp text matters most.
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Frequently asked questions
How much bigger is the 40″ ultrawide 5K2K than the 38″ ultrawide?
The 40″ ultrawide 5K2K has 12% more screen area (573 vs 513 square inches) and is 1.8″ wider.
Which is sharper, the 38″ ultrawide or the 40″ ultrawide 5K2K?
The 40″ ultrawide 5K2K is sharper at 139 PPI versus 109 PPI on the 38″ ultrawide, a 27% increase in pixel density.
Which is better for a Mac, the 38″ ultrawide or the 40″ ultrawide 5K2K?
The 38″ ultrawide is the better fit (sharp, not Retina). It runs at native 3840 × 1600, with a comfortable UI size and clean pixel mapping. Text is sharp, but you may notice individual pixels up close.
Which is better for gaming, the 38″ ultrawide or the 40″ ultrawide 5K2K?
The 38″ ultrawide has 44% fewer pixels to render, so the same graphics card reaches higher frame rates on it. The 40″ ultrawide 5K2K shows finer detail but needs 1.80× the GPU work per frame. Refresh rate and panel type matter as much as size.
Will a 40″ ultrawide 5K2K fit on my desk?
Its screen is 36.9″ (94 cm) wide; allow about 1″ (2–3 cm) more for the frame. For comfortable viewing, a desk at least 86 cm (34″) deep works best, or use a monitor arm to push it back.
How far should I sit from a 40″ ultrawide 5K2K?
About 40″ (102 cm) is comfortable, so the full screen height stays within a relaxed field of view.
Last updated October 8, 2026. Figures are calculated from panel diagonal and resolution; bezels and stands vary by model.