Calculators
TV size and viewing distance calculator
Television size is a geometry problem with one variable people never measure: how far away they actually sit.
On this page (3 sections)
Short answer
For 4K, a comfortable screen fills 30 to 40 degrees of your field of view, which puts the seating distance at roughly 1.2 to 1.6 times the screen diagonal. From 9 ft (2.7 m), that is a 65 to 90 in screen.
The numbers, at a glance
- 4K seating distance
- Diagonal x 1.2 to 1.6
- 1080p seating distance
- Diagonal x 1.6 to 2.5
- Screen centre height
- About 42 in (107 cm)
- 16:9 screen height
- Diagonal x 0.49
TV size and viewing distance calculator#
Works in both directions: give it a seating distance and it returns the screen size range, or give it a screen size and it returns where the sofa should sit.
Nothing you type leaves your browser: the maths runs on this page, and no values are stored or sent anywhere.
The geometry behind it#
Screen size recommendations are really field-of-view recommendations. SMPTE's reference viewing condition puts the screen at about 30 degrees of horizontal field of view; THX recommends closer to 36 to 40 degrees for cinema immersion. Convert those angles into a distance for a 16:9 screen and you get the familiar multipliers: about 1.6 times the diagonal for the SMPTE angle and about 1.2 for the THX angle.
Resolution sets the near limit. At 1080p, sitting closer than about 1.6 times the diagonal starts to make the pixel structure visible on a normal panel. At 4K it does not, which is why the entire recommended band moved closer when 4K arrived and why the "too big" instinct most people have is calibrated to a format that no longer exists in the shops.
Height matters more than most people think#
A 16:9 screen is 0.49 times its diagonal in height. That means a 75 in television is 36.8 in (93 cm) tall, and where you put its centre determines whether you spend two hours with your neck in a neutral position or extended.
Seated eye height on a typical sofa is 38 to 44 in (97 to 112 cm). Put the screen centre there and the gaze is level. Every inch above that is an inch of neck extension, and the effect compounds because the top of the screen is half the screen height above the centre.
Practical checks before you buy#
- Measure from the eye position on the seat you actually use, not from the wall.
- Add the stand height or subtract the mount offset before deciding the centre height.
- Check the off-axis seats: most LCD panels lose contrast noticeably beyond about 30 degrees off centre, while OLED holds up much further.
- Leave 2 to 4 in (5 to 10 cm) behind a wall-mounted set for cables, and put the outlet behind the screen, not below it.
The full guide to TV size and height covers glare, soundbar space and off-axis seating in more detail.
Frequently asked questions#
How far should I sit from a 65 inch TV?
Between 6 ft 6 in and 8 ft 8 in (2.0 to 2.6 m) for 4K content. Closer than 6 ft 6 in and you begin scanning rather than seeing the whole frame; further than about 10 ft and the extra resolution of a 4K panel stops being visible at all.
What size TV for a 10 ft viewing distance?
75 to 100 in diagonal at 4K. Most people in that position buy a 65 in set and then sit wondering why the cinema felt more immersive. The answer is field of view, not picture quality.
What should I enter for seated eye height?
Sit on the seat you actually watch from, have someone measure from the floor to the centre of your eye, and enter that. It is 38 to 44 in (97 to 112 cm) for most adults on a normal sofa, lower on a deep lounge seat and higher on a firm upright chair. The default of 42 in (107 cm) is a middle value, not a standard.
Is mounting a TV above a fireplace really that bad?
It is a measurable compromise. A mantel at 48 in (122 cm) plus clearance puts a 65 in screen's centre near 70 in (178 cm), roughly 28 in above seated eye level. At 9 ft that is about 13 degrees of upward gaze for the centre and more for the top of the frame. It is tolerable for occasional viewing and tiring for a film. A pull-down or tilting mount reduces it.
Sources and standards referenced#
- SMPTE EG 18-1994 recommended viewing conditions Society of Motion Picture and Television Engineers30 degree horizontal field of view reference
- THX certified cinema viewing angle recommendations THXApproximately 36 to 40 degrees for an immersive image
- Human Dimension and Interior Space Panero and ZelnikSeated eye height data
We cite published codes, industry planning guidelines and manufacturer specifications. Where a figure is our own recommendation rather than a published standard, the text says so. See how we measure.