TV Size & Viewing Distance Calculator
Enter your TV's diagonal size and resolution to get the ideal viewing distance recommended by SMPTE standards, or enter your room's viewing distance to find the best TV size for that seat.
Screen resolution
inches
ft
Optimal for 4K — 1.92 m / 192 cm
- 1
TV diagonal in cm
55 × 2.54 = 139.7 - 2
Ideal distance (40° viewing angle)
139.7 ÷ (2 × tan(20°)) = 191.9tan(20°) ≈ 0.364 for 4K content. - 3
Convert to feet
191.9 ÷ 30.48 = 6.3
How does this calculator work?
Ideal viewing distance equals the TV diagonal in cm divided by (2 × tan(half the recommended angle)): 40° for 4K, 30° for 1080p. For a 55-inch 4K TV that is about 1.75 m (5.7 ft); for a 55-inch 1080p TV, about 2.2 m (7.2 ft). Sitting closer makes 4K detail visible.
Formula
How this is calculated
The Society of Motion Picture and Television Engineers (SMPTE) standard 196M defines the recommended viewing angle — the horizontal arc the screen subtends at the viewer's eye — as 30° for standard HD content. At a 30° angle your visual system resolves the full detail of a 1080p image without perceiving individual pixels at a normal distance. For 4K and 8K panels, a larger angle (40°) is recommended because the higher pixel density means you can sit closer while still seeing smooth edges — and sitting closer is also how you get the full benefit of the extra resolution.
The formula works geometrically: the screen diagonal in centimetres divided by (2 × tangent of half the viewing angle) gives the perpendicular distance from screen to eye at which the screen exactly fills the recommended arc. The calculator also shows a practical range: the minimum distance corresponds to 36° (closer than that is fatiguing for most people) and the maximum to 16° (beyond which resolution is wasted).
Enter your actual seating distance to find the ideal TV size for that spot, and to see the real viewing angle your current TV subtends. Distances and sizes are estimates — they assume a flat screen viewed straight on, at eye height with the screen centre, in a well-lit room. Curved screens and off-axis viewing change the geometry somewhat.
Frequently asked questions
Yes. At the "1080p optimal" distance of about 1.87× the screen height, your eyes cannot resolve the individual pixels of a 4K screen — they appear identical to 1080p. Sitting at the 4K-optimal distance (about 1.2× the screen height) lets you see the finer detail that 4K provides.
The "2–2.5 times the diagonal" rule is a rough approximation for 1080p that predates 4K. The angle-based method is content- and resolution-aware: a 4K screen rewards a closer seat, while the old rule would place you too far away to benefit from the extra pixels.
Optimise for the primary viewing seat. For a sofa at a fixed distance the calculator tells you the best screen size. If viewers sit at different distances, aim for the midpoint or consider the comfort of the person nearest the screen (overly large or bright screens are harder on those seated close).
Also known as
TG we-Calculate Editorial Team. (2026). TV Size & Viewing Distance Calculator [Online calculator]. TG we-Calculate. https://we-calculate.com/calculator/tv-size-distance-calculator
TG we-Calculate Editorial Team. "TV Size & Viewing Distance Calculator." TG we-Calculate. 2026. https://we-calculate.com/calculator/tv-size-distance-calculator.
TG we-Calculate Editorial Team, "TV Size & Viewing Distance Calculator," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/calculator/tv-size-distance-calculator
@misc{wecalculate_tv_size_distance_calculator, title = {TV Size & Viewing Distance Calculator}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/calculator/tv-size-distance-calculator}}, year = {2026}, note = {TG we-Calculate} }
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