How we calculate it
A TV's size is its diagonal, but what your eyes care about is the viewing angle— how much of your field of view the screen fills. Industry guidelines pin three useful targets:
- Comfortable — SMPTE 30°. The Society of Motion Picture and Television Engineers' reference for relaxed viewing. Diagonal ≈ distance × 0.61.
- Sweet spot — ~33°. A practical middle ground most people prefer. Diagonal ≈ distance × 0.69.
- Immersive — THX 40°. THX's recommendation for a cinema-like field of view. Diagonal ≈ distance × 0.84.
For a 16:9 screen the width is the diagonal × 0.8716 and the height is × 0.4903. The viewing angle is θ = 2 · atan( (width ⁄ 2) ÷ distance ), and we invert it to get the recommended diagonal for each target angle.
Resolution sets how close you can sit before pixels show: about 1.5× screen height for 4K, 2.5× for 1080p, and 0.7× for 8K. That's why 4K lets you size up or sit closer, while 1080p is happier toward the comfortable end.
Quick reference: distance → recommended size
| Seating distance | Comfortable | Sweet spot | Immersive |
|---|---|---|---|
| 5 ft | 37" | 41" | 50" |
| 6 ft | 44" | 50" | 60" |
| 7 ft | 51" | 58" | 71" |
| 8 ft | 59" | 66" | 81" |
| 9 ft | 66" | 75" | 91" |
| 10 ft | 73" | 83" | 101" |
| 12 ft | 88" | 99" | 121" |
| 15 ft | 110" | 124" | 151" |
Frequently asked questions
- What size TV is best for my room?
- Multiply your seating distance (in inches) by about 0.69 for the sweet spot — roughly a 33° viewing angle. For a 9 ft (108 in) distance that's about a 75-inch TV. Use the comfortable end (×0.61) for casual viewing and the immersive end (×0.84) for movies and gaming.
- How far should I sit from a TV?
- It depends on size and resolution. For 4K you can sit as close as about 1.5× the screen height without seeing pixels, so a 65-inch 4K TV (≈32 in tall) works from around 4 ft and up. 1080p needs roughly 2.5× the screen height.
- Will a TV fit on my wall?
- Enter your wall width above. As a rule of thumb the TV's width should be no more than about 75% of the wall so it has visual breathing room and clears speakers, shelves and mounts. The calculator flags it when a size gets too tight.
- Is a bigger TV always better?
- No. Past roughly a 40° viewing angle (THX immersive) you start moving your eyes and neck to take in the whole picture, which gets tiring, and on lower resolutions you'll see pixels. Bigger also means more weight on the mount and stand.
- How high should I mount my TV?
- Put the center of the screen near seated eye level — about 105–120 cm (42–48 in) off the floor for a typical sofa. Mounting too high is the most common cause of neck strain.