Size for distance / 15 feet
What size TV for 15 feet away?
From 15 feet (180 in, 457 cm), a 111-inch screen fills the SMPTE 30° everyday view and a 150-inch screen fills THX's 40° cinema view. Sizes in that range listed here: 115".
The numbers for 15 feet
| Basis | Screen size | Screen width | Reading it |
|---|---|---|---|
| SMPTE 30° (mixed viewing) | 111" | 96.5 in | The screen fills 30° of your view — the comfortable everyday figure. |
| THX 40° (cinema) | 150" | 131 in | The screen fills 40° — immersive for film, a lot for news and sport all day. |
| 4K's own pixels visible from | 231" | 201.1 in | Only screens this big show 4K's pixels to 20/20 eyes from 15 ft — the point where 8K would start to help. |
| 4K looks sharper than 1080p from | 115" | 100.5 in | On smaller screens, 1080p already reaches the limit of 20/20 vision from 15 ft, so 4K adds no visible sharpness. |
At 15 feet the point where 4K looks sharper than 1080p, 115 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 15 feet on a 231-inch screen — larger than any TV listed — which is why 8K adds nothing you can see at this distance.
What a 15-foot room usually looks like
Fifteen feet is the back row of a home theater or a long converted garage. Rooms like this are normally built around a projector, with a TV as the daytime screen.
15 feet is beyond what any TV listed here can fill to the 40° cinema view — that would take a 150-inch screen, while the largest listed is 115 inches. Even the 30° everyday view needs 111 inches. Rooms this deep are projector rooms, or rooms where the seating should move closer to a large TV.
Compared with 14 feet, every extra foot of distance adds about 7 inches to the SMPTE size and 10 to the THX size. The SMPTE size is within reach of the largest TVs listed; the THX size is not.
Choosing within the range
The two standards bracket a sensible choice rather than giving one answer. Lean toward 111 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 150 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 15 feet
- 115-inch: 4 models, e.g. LG 115QNED92BU, Samsung MRN115MR95FXZA
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).