Size for distance / 4 feet
What size TV for 4 feet away?
From 4 feet (48 in, 122 cm), a 30-inch screen fills the SMPTE 30° everyday view and a 40-inch screen fills THX's 40° cinema view. Sizes in that range listed here: 32".
The numbers for 4 feet
| Basis | Screen size | Screen width | Reading it |
|---|---|---|---|
| SMPTE 30° (mixed viewing) | 30" | 25.7 in | The screen fills 30° of your view — the comfortable everyday figure. |
| THX 40° (cinema) | 40" | 34.9 in | The screen fills 40° — immersive for film, a lot for news and sport all day. |
| 4K's own pixels visible from | 62" | 53.6 in | Only screens this big show 4K's pixels to 20/20 eyes from 4 ft — the point where 8K would start to help. |
| 4K looks sharper than 1080p from | 31" | 26.8 in | On smaller screens, 1080p already reaches the limit of 20/20 vision from 4 ft, so 4K adds no visible sharpness. |
At 4 feet the point where 4K looks sharper than 1080p, 31 inches, falls between the SMPTE and THX sizes: at the everyday size the difference is marginal, at the cinema size it is visible. 4K's own pixels only become visible from 4 feet on a 62-inch screen.
What a 4-foot room usually looks like
Four feet is gaming-chair and desk distance: a console player pulled up close, or a TV doubling as a computer screen. Text legibility matters more than immersion here, so resolution counts for more than size.
4 feet is desk, dorm and small-bedroom territory: a TV on a dresser opposite the bed, or a screen used as a monitor from a sofa pushed close. At this distance the screen sits in your direct field of view, so the smaller end of the range is usually more comfortable, and from 31 inches up, 4K's extra resolution reads as sharper text and finer detail.
Each extra foot of distance adds about 7 inches to the SMPTE size. Both sizes are within the range of TVs listed here.
Choosing within the range
The two standards bracket a sensible choice rather than giving one answer. Lean toward 30 inches for a room used for news, sport, gaming at a desk distance, or a bright room where a huge black rectangle dominates when the set is off. Lean toward 40 inches for a room built around films. Your eyes, not the chart, settle it: if you turn your head to follow the action, the screen is past 40° for you; if you lean forward to read captions, it is under 30°.
Measure from where your eyes are when seated to where the screen will be — not from the wall. A TV on a stand sits several inches in front of the wall, and a full-motion mount can bring it forward a foot or more. For comparison, the SMPTE distance for a 55-inch is 7 ft 5 in and the THX distance for a 65-inch is 6 ft 6 in.
TVs to look at for 4 feet
- 32-inch: 4 models, e.g. LG 32LR655BPUA, LG 32LB650BPUA
Sizes are geometry from the viewing angles and the 20/20 acuity limit cited by Wikipedia's Optimum HDTV viewing distance article, for a 16:9 screen. Viewing distances are geometry from published viewing angles: a 16:9 screen's width is 0.8716 x its diagonal, and the distance at which it fills a horizontal angle A is width / (2 x tan(A/2)). Resolution distances use the 20/20 acuity limit of one arcminute per pixel. The same formulas reproduce the reference figures quoted in the source (30 degrees = 1.6264 x diagonal; 31.2 degrees for 1080p; 58.37 degrees for 4K).