How to use the TV viewing distance calculator
Buying a TV from a diagonal alone is how living rooms end up with a screen that feels tiny or overwhelming. This calculator links diagonal, seating distance, field of view and wall-mount height so the picture and the sofa agree.
- Choose units and whether you already know the screen size or the seating distance.
- Enter the diagonal or the viewing distance, and keep 16:9 unless you are sizing an ultrawide display.
- Pick a distance preference: everyday mixed use, SMPTE (~30°) or THX (~40°).
- Set seated eye height (or seat height) to get the mount height to the centre and to the bottom of the screen.
Viewing distance and mount formulas
Screen height = diagonal / √(1 + (W/H)²) (16:9 → ≈ 0.490 × diagonal)
Screen width = height × (W/H) (16:9 → ≈ 0.872 × diagonal)
SMPTE distance ≈ 1.6 × height (~30° FOV)
THX distance ≈ 1.2 × height (~40° FOV)
Everyday band ≈ diagonal × 1.5 to 2.5
FOV = 2 × atan((width / 2) / distance)
Mount to centre ≈ eye height | Mount to bottom ≈ eye height − height / 2
| Diagonal | 16:9 height | SMPTE ~30° | THX ~40° | Everyday band |
|---|---|---|---|---|
| 55 in | 27 in | ~3.6 ft | ~2.7 ft | 6.9–11.5 ft |
| 65 in | 32 in | ~4.2 ft | ~3.2 ft | 8.1–13.5 ft |
| 75 in | 37 in | ~4.9 ft | ~3.7 ft | 9.4–15.6 ft |
| 85 in | 42 in | ~5.5 ft | ~4.2 ft | 10.6–17.7 ft |
Cinema standards put you closer than many living-room habits. Use SMPTE/THX when the room is a dedicated media space; use the everyday band when the sofa also serves conversation and daylight viewing.
Worked examples
A 65 in TV in a typical lounge
Height is about 32 in. SMPTE distance is roughly 4.2 ft and THX about 3.2 ft, while the everyday band is 8–13.5 ft. If the sofa sits 10 ft away, FOV is about 26°, a comfortable living-room angle. With eye height at 42 in, mount the centre at 42 in and the bottom at about 26 in above the floor.
Choosing a size for a 3 m sofa distance
At 3 m (about 9.8 ft), an everyday 1.5–2.5 × diagonal band points to roughly a 47–79 in screen. A 65 in TV is right in the middle; a 75 in screen is still within the band and closer to a 30° FOV.
Bedroom TV above a dresser
Viewing from a bed often means a higher eye line and a downward gaze. Raise the entered eye height toward 48–50 in if you watch propped up, or tilt the mount, and keep the bottom of the screen clear of the dresser top by an inch or two for ventilation.
Who this calculator helps
- Interior designers and architects placing media walls and sofa depths on plans.
- Homeowners choosing between 55, 65, 75 and 85 in before buying.
- AV installers setting bracket height and confirming FOV for clients.
- Developers and staging teams standardising living-room media niches.
Practical tips
- Check seating clearances with the furniture clearance guide and room proportions with the golden ratio calculator.
- Size ambient light and glare with the lighting calculator and daylight with the daylight factor calculator.
- Leave cable and soundbar space below the screen; a soundbar can add 2–3 in under the panel.
- For fireplace mounts, prefer a pull-down or tilting bracket and accept a higher centre only if tilt aims at eye level.
- Measure distance from eye to screen centre, not from the wall to the sofa back.
Want to preview the media wall and sofa before you buy? Try the layout on a photo with Room Redesign.
