A 24″ monitor is the same physical size — about 20.9″ wide by 11.8″ tall — whatever resolution you pick. What changes is pixel density: more pixels in that fixed area means smaller pixels, sharper text and finer detail. Here's how FHD vs QHD compare on a 24″ screen.
| Resolution | Pixels | PPI | Pixel pitch | How it feels |
|---|---|---|---|---|
| FHD | 1920 × 1080 | 92 | 0.277 mm | On the coarse side — pixels and soft text are visible |
| QHD | 2560 × 1440 | 122 | 0.208 mm | Sharp — you may prefer slight UI scaling |
Because the diagonal is fixed, a higher resolution doesn't make the screen bigger — it makes each pixel smaller, so text and edges look crisper. The trade-off is that the interface also shrinks: past roughly ~150 PPI you'll usually want to turn on OS scaling to keep menus and text readable.
For a normal desk viewing distance, about ~95–120 PPI is the comfortable band where the UI reads well at 100% scaling. On a 24″ panel that means FHD sits at ~92 PPI (on the coarse side — pixels and soft text are visible), while QHD reaches ~122 PPI (sharp — you may prefer slight UI scaling) — same screen, noticeably different sharpness.
Viewing distance matters too: the farther you sit, the less a lower PPI shows, so a higher resolution pays off most when the screen is close.