TV Size and Viewing Distance Calculator
From 9 ft away, the screen that fills a 30° (SMPTE) to 36° (THX) view is a 66–81 inch 16:9 TV. For a 65-inch TV, sit 7.3–8.8 ft (2.2–2.7 m): a 65-inch 16:9 screen is 56.7 × 31.9 in, and distance = (width ÷ 2) ÷ tan(angle ÷ 2). Enter a seating distance for a TV size, or a TV size for the distance range. Mount the screen with its centre about 42 in (107 cm) off the floor, guidance for seated eye level.
Updated Runs in your browser: nothing you enter is uploadedHow this tool works
Worked out in your browser for a 16:9 screen. Results show feet and inches alongside meters and centimeters.
What size TV for my seating distance?
66–81 inch TV
diagonal = distance × 2 × tan(angle ÷ 2) × √337 ÷ 16. At 9 ft: 66.4 in at 30°, 80.5 in at 36°.
- Seating distance
- 9 ft (2.74 m)
- Balanced (SMPTE 30°)
- 66.4 in (168.7 cm)
- Immersive (THX 36°)
- 80.5 in (204.5 cm)
- Smallest at the 26° limit
- 57.2 in (145.3 cm)
- Common sizes in the range
- 75 in, 77 in
- 1080p pixels visible on screens over
- 69 in (176 cm)
- 4K pixels visible on screens over
- 138 in (352 cm)
- 8K pixels visible on screens over
- 277 in (703 cm)
How far should I sit from my TV?
7.3–8.8 ft (2.2–2.7 m)
width = 65 × 16 ÷ √337 = 56.65 in; distance = (width ÷ 2) ÷ tan(angle ÷ 2) = 87.2 in at 36°, 105.7 in at 30°.
- Screen width × height
- 56.7 × 31.9 in (143.9 × 80.9 cm)
- Immersive (THX 36°)
- 7.3 ft (2.21 m)
- Balanced (SMPTE 30°)
- 8.8 ft (2.69 m)
- Farthest (THX 26°)
- 10.2 ft (3.12 m)
- 1080p: closer than this you can see pixels
- 8.5 ft (2.58 m)
- 4K: closer than this you can see pixels
- 4.2 ft (1.29 m)
- 8K: closer than this you can see pixels
- 2.1 ft (0.64 m)
- Mount height, centre of screen (guidance)
- 42 in (107 cm)
- Mount height, bottom edge (guidance)
- 26.1 in (66.2 cm)
Viewing distance by TV size (16:9)
| Diagonal | Width × height (in) | 36° THX | 30° SMPTE | 26° limit |
|---|---|---|---|---|
| 32″ | 27.9 × 15.7 | 3.6 ft (1.1 m) | 4.3 ft (1.3 m) | 5 ft (1.5 m) |
| 43″ | 37.5 × 21.1 | 4.8 ft (1.5 m) | 5.8 ft (1.8 m) | 6.8 ft (2.1 m) |
| 50″ | 43.6 × 24.5 | 5.6 ft (1.7 m) | 6.8 ft (2.1 m) | 7.9 ft (2.4 m) |
| 55″ | 47.9 × 27 | 6.1 ft (1.9 m) | 7.5 ft (2.3 m) | 8.7 ft (2.6 m) |
| 65″ | 56.7 × 31.9 | 7.3 ft (2.2 m) | 8.8 ft (2.7 m) | 10.2 ft (3.1 m) |
| 75″ | 65.4 × 36.8 | 8.4 ft (2.6 m) | 10.2 ft (3.1 m) | 11.8 ft (3.6 m) |
| 85″ | 74.1 × 41.7 | 9.5 ft (2.9 m) | 11.5 ft (3.5 m) | 13.4 ft (4.1 m) |
| 98″ | 85.4 × 48 | 11 ft (3.3 m) | 13.3 ft (4 m) | 15.4 ft (4.7 m) |
TV size by seating distance (16:9)
| Distance | Balanced, 30° SMPTE | Immersive, 36° THX |
|---|---|---|
| 5 ft (1.5 m) | 37″ | 45″ |
| 6 ft (1.8 m) | 44″ | 54″ |
| 7 ft (2.1 m) | 52″ | 63″ |
| 8 ft (2.4 m) | 59″ | 72″ |
| 9 ft (2.7 m) | 66″ | 81″ |
| 10 ft (3 m) | 74″ | 89″ |
| 12 ft (3.7 m) | 89″ | 107″ |
| 14 ft (4.3 m) | 103″ | 125″ |
Resolution limit: how close before you see pixels
| Diagonal | 1080p | 4K | 8K |
|---|---|---|---|
| 32″ | 4.2 ft (1.27 m) | 2.1 ft (0.63 m) | 1 ft (0.32 m) |
| 43″ | 5.6 ft (1.7 m) | 2.8 ft (0.85 m) | 1.4 ft (0.43 m) |
| 50″ | 6.5 ft (1.98 m) | 3.3 ft (0.99 m) | 1.6 ft (0.5 m) |
| 55″ | 7.2 ft (2.18 m) | 3.6 ft (1.09 m) | 1.8 ft (0.55 m) |
| 65″ | 8.5 ft (2.58 m) | 4.2 ft (1.29 m) | 2.1 ft (0.64 m) |
| 75″ | 9.8 ft (2.97 m) | 4.9 ft (1.49 m) | 2.4 ft (0.74 m) |
| 85″ | 11.1 ft (3.37 m) | 5.5 ft (1.68 m) | 2.8 ft (0.84 m) |
| 98″ | 12.7 ft (3.88 m) | 6.4 ft (1.94 m) | 3.2 ft (0.97 m) |
How to choose a TV size and seating distance
- Measure from your eyes to the screen. Measure from where you sit to where the TV will be, in feet or meters. For example 9 ft is 2.74 m.
- Pick a viewing angle. 30° (SMPTE) is a balanced view; 36° (THX) is more immersive for movies. At 9 ft that is 66–81 inch TV.
- Turn the angle into a size. Screen width = 2 × distance × tan(angle ÷ 2), then diagonal = width × √337 ÷ 16 for a 16:9 screen.
- Or start from a TV. A 65-inch 16:9 TV is 56.7 × 31.9 in. Seat distance = (width ÷ 2) ÷ tan(angle ÷ 2) = 7.3 ft (2.21 m) at 36° and 8.8 ft (2.69 m) at 30°.
- Set the mount height. Put the centre of the screen near seated eye level, about 42 in. For the 65-inch TV the bottom edge is then 26.1 in from the floor.
Frequently asked questions
- How far should I sit from a 65-inch TV?
- About 7.3–8.8 ft (2.2–2.7 m): 7.3 ft (2.21 m) for a 36° THX view to 8.8 ft (2.69 m) for the 30° SMPTE view. Your own comfort decides inside that range.
- What size TV should I buy for a 9-foot viewing distance?
- 66–81 inch, from the 30° and 36° angles at 9 ft. Common sizes in that range: 75 in, 77 in.
- What viewing angle do SMPTE and THX recommend?
- SMPTE’s recommended practice for HD viewing is about 30° of horizontal view. THX is usually quoted at 36° for the farthest seat in a theatre, with about 26° described as the least acceptable. Some retailers quote up to 40° for a very immersive seat, but that figure is not confirmed in the sources used here, so this tool stops at 36°.
- How do you calculate the width of a 16:9 TV from its diagonal?
- Width = diagonal × 16 ÷ √(16² + 9²) = diagonal × 16 ÷ √337, and height = diagonal × 9 ÷ √337. A 65-inch TV is 56.7 × 31.9 in (143.9 × 80.9 cm). Screen sizes exclude the bezel.
- Can I see the difference between 1080p and 4K?
- Only if you are close enough. With 20/20 vision, a pixel is resolvable inside about 7.2 ft for a 55-inch 1080p screen and 3.6 ft for 55-inch 4K. Farther than that, the extra pixels are below the eye’s resolving power, though contrast, HDR and colour still differ.
- How high should I mount a TV on the wall?
- A common guide is the centre of the screen at seated eye level, about 42 in (107 cm) from the floor. That puts a 65-inch TV’s bottom edge at 26.1 in and top at 57.9 in. This is guidance, not a standard: measure your own eye height seated.
- Is a bigger TV always better?
- Not past the angle you find comfortable. A TV bigger than the 36° size for your seat fills more than the THX figure, so you turn your head to see the edges. Content also matters: low-resolution video looks soft on a large screen up close.
How it works
A 16:9 screen with diagonal d has width d × 16 ÷ √337 and height d × 9 ÷ √337, because 16² + 9² = 337. The horizontal angle θ that a screen of width w fills from distance D satisfies tan(θ ÷ 2) = (w ÷ 2) ÷ D, so D = (w ÷ 2) ÷ tan(θ ÷ 2); solving for w gives the size for a distance. The recommended range runs from 36° (closest, THX) to 30° (farthest, SMPTE); 26° (THX) is shown as an outer limit. The resolution limit assumes 20/20 vision resolves 1 arcminute: a pixel row is the screen height divided by the vertical pixel count (1080, 2160, 4320), and the limit distance is that pitch divided by tan(1/60°). Real eyes, content and lighting vary, so treat all of this as a starting point. The mount height is a rule of thumb: the screen centre at about 42 in (107 cm), matching a seated eye level. 1 inch = 2.54 cm exactly. Everything runs in your browser.
Sources
- Sound & Vision, “Screen Size and Seating Distance” (SMPTE 30° and THX 36°/26° viewing angles)
- KEF, “How to calculate the proper height for your television” (viewing angle and mounting height)
- SMPTE’s roughly 30° horizontal viewing angle for HD and THX’s 36° back-row angle, as reported by the two sources above (the standards text itself is paywalled)
- Snellen acuity: 20/20 vision resolves detail of 1 arcminute
- NIST Special Publication 811 (1 inch = 2.54 cm exactly)
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