Size for distance / 9 feet

What size TV for 9 feet away?

From 9 feet (108 in, 274 cm), a 66-inch screen fills the SMPTE 30° everyday view and a 90-inch screen fills THX's 40° cinema view. Sizes in that range listed here: 70", 75", 77", 83", 85", 86".

SMPTE 30° everyday
66"
THX 40° cinema
90"
4K beats 1080p from
69"
Models in range
76
9 ft 30° → 66"40° → 90"
Seen from above, to scale: the screen widths that fill 30° and 40° of your view from 9 ft.

The numbers for 9 feet

BasisScreen sizeScreen widthReading it
SMPTE 30° (mixed viewing)66"57.9 inThe screen fills 30° of your view — the comfortable everyday figure.
THX 40° (cinema)90"78.6 inThe screen fills 40° — immersive for film, a lot for news and sport all day.
4K's own pixels visible from138"120.6 inOnly screens this big show 4K's pixels to 20/20 eyes from 9 ft — the point where 8K would start to help.
4K looks sharper than 1080p from69"60.3 inOn smaller screens, 1080p already reaches the limit of 20/20 vision from 9 ft, so 4K adds no visible sharpness.

At 9 feet the point where 4K looks sharper than 1080p, 69 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 9 feet on a 138-inch screen — larger than any TV listed — which is why 8K adds nothing you can see at this distance.

What a 9-foot room usually looks like

Nine feet is a roomy living room with a coffee table between sofa and screen. Two people on a three-seat sofa sit at noticeably different angles here, so a screen at eye level matters as much as its size.

9 feet is the most common living-room distance: a sofa against one wall and the TV on the opposite one. This is where the jump from a 55-inch to a 65- or 75-inch set pays off most, because both standards land in that band; 4K pulls ahead of 1080p from 69 inches at this distance.

Compared with 8 feet, every extra foot of distance adds about 7 inches to the SMPTE size and 10 to the THX 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 66 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 90 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 9 feet

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).