TV size guide vs Viewing distance formula
Side-by-side comparison, when-to-use-each guide, and instant conversion. Reviewed for 2026.
Choosing a screen size for a known room.
Choosing a room layout for a screen, or checking an existing setup.
| Aspect | TV size guide | Viewing distance formula |
|---|---|---|
| 40" TV (HD) | — | 7-8 ft / 2.1-2.4m |
| 55" TV (HD) | — | 8.5-10 ft / 2.6-3m |
| 55" TV (4K) | — | 5-7 ft / 1.5-2.1m |
| 65" TV (4K) | — | 6-8 ft / 1.8-2.4m |
| 75" TV (4K) | — | 7-9 ft / 2.1-2.7m |
Frequently asked
What size TV for a 3m x 4m room?
With a typical sofa at ~2.5-3m viewing distance, a 55-65" 4K TV is ideal. At that distance, 4K is noticeable over HD on a 55"+ screen. Go 65" if budget allows — most people who buy a 55" wish they'd gone bigger.
Does TV size affect eye strain?
Optimal distance and correct room brightness matter more than screen size. Sitting too close for the resolution causes eye strain; sitting too far means you can't see the detail. Modern OLED/QLED TVs with HDR and proper brightness calibration cause less eye strain than older LCD TVs.
Frequently asked questions
What size TV for a 3m x 4m room?
With a typical sofa at ~2.5-3m viewing distance, a 55-65" 4K TV is ideal. At that distance, 4K is noticeable over HD on a 55"+ screen. Go 65" if budget allows — most people who buy a 55" wish they'd gone bigger.
Does TV size affect eye strain?
Optimal distance and correct room brightness matter more than screen size. Sitting too close for the resolution causes eye strain; sitting too far means you can't see the detail. Modern OLED/QLED TVs with HDR and proper brightness calibration cause less eye strain than older LCD TVs.