What size TV for a 3 m viewing distance?
73-inch to 99-inch from 3.0 m (9 ft 10 in)
From 3.0 m (9 ft 10 in) away, a 73-inch TV fills 30° of your view (the SMPTE figure) and a 99-inch TV fills 40° (THX's). A 75-inch screen, the nearest size shops stock, fills 31° from that seat.
Both figures come from cinema practice, so they give a large screen. Read them as the size at which the picture fills your view the way a cinema's does. A smaller screen from the same seat is still a good picture; it only fills less of what you see.
Work the other way too. If the size you can afford or fit on the wall is fixed, the calculator tells you how far to sit from it, and whether moving the sofa a little closer would do more for the picture than a bigger screen.
Worked out for A seat 3.0 m (9 ft 10 in) from the screen, and a screen in the usual wide shape. Change the numbers
The working
- From 3.0 m the SMPTE figure, 30° of your view, needs a 73-inch screen.
- From the same seat THX's figure, 40°, needs a 99-inch screen.
- A 75-inch screen from 3.0 m fills 31°.
The rules, and their sources
SMPTE 30°
The screen fills 30° of your view when you sit about 1.6 times its diagonal away. It is widely quoted as the SMPTE figure.
An industry guideline Sources: Wikipedia, Optimum HDTV viewing distance (checked 31 October 2026); Audioholics, How to find the right size TV (checked 15 October 2026).
THX 40°
THX's best seat fills 40° of your view, about 1.2 times the diagonal away. THX's own range runs from 40° (closest) to about 28° (farthest).
An industry guideline Source: Wikipedia, Optimum HDTV viewing distance (checked 31 October 2026).
Other distances
Measure from where your eyes are when you sit to the wall the screen goes on, then read across.
| Seat to screen | Fills 30° (SMPTE) | Fills 40° (THX) |
|---|---|---|
| 2.0 m (6 ft 7 in) | 48-inch | 66-inch |
| 2.5 m (8 ft 2 in) | 61-inch | 82-inch |
| 3.0 m (9 ft 10 in) this page | 73-inch | 99-inch |
| 3.5 m (11 ft 6 in) | 85-inch | 115-inch |
| 4.0 m (13 ft 1 in) | 97-inch | 132-inch |
Change the numbers
Your sizes will differ. The TV height and distance calculator opens with these numbers filled in: change any of them and the answer, the working and the drawing follow.
Editorial notes
Worked out by the Snuug team on 12 November 2026 with the same code as the TV height and distance calculator, so the two cannot disagree. Every rule cites its source, with the date we last checked it. A rule designers use is a convention, not a study.
Other sources the calculator draws on:
- Acoustic Frontiers, Home theater viewing angles, distances and sightlines (CEDIA, 15°), checked 31 October 2026