What size TV should you buy?
The right size is usually bigger than people guess, but there is an honest limit to it. This works both ways: Give it your seat distance for a size, or give it a size for the seat. Either way it tells you the part the shop leaves out: Whether 4K, or 8K, is even visible from where you sit.
How far will you sit?
Recommended screen size
65"
Anywhere from 55 to 75 inch works: bigger is more cinematic, smaller is more relaxed.
To scale
Verdict
Which TV size are you looking at?
Best seat distance
2.0 to 2.7 m
Ideal about 2.2 m.
To scale
Verdict
Quick answer
Aim for a screen diagonal roughly two-thirds to four-fifths of your seat distance. For a seat about 2.5 m (8 ft) back that points at a 65 to 75 inch TV, and when in doubt, size up. Whether the extra pixels are visible depends on the same distance: The eye resolves about one sixtieth of a degree, so past a certain distance 4K looks identical to 1080p, and the pixels of an 8K screen vanish closer still. The calculator marks where your seat falls.
How the size is worked out
The size range comes from how much of your view the screen fills. The film industry frames this as a viewing angle: SMPTE puts a relaxed setup at about 30 degrees across, and THX a cinematic one at about 40. In plain numbers that means a screen whose diagonal is roughly two-thirds to four-fifths of your seat distance. The calculator snaps to the nearest real TV size, so you get a number you can actually buy.
Why 4K is often wasted, and 8K almost always
Your eye can only resolve so much detail, about one sixtieth of a degree with good vision. Past a certain distance the pixels on a 4K screen blur together and the picture looks identical to 1080p, and that distance is closer than most sofas. The pixels on an 8K screen vanish closer still, which is why it is the emptiest number in the showroom. The strip under the verdict marks exactly where your seat falls. To see what your own set is really doing, run the resolution test or read is my TV really 4K.
Questions people ask
What size TV should I buy for my room?
Measure how far your seat is from the wall, then aim for a screen diagonal roughly two-thirds to four-fifths of that. For a seat about 2.5 m (8 ft) back, that points at a 65 to 75 inch set. When in doubt, size up: The regret almost always runs the other way.
Is a bigger TV always better?
Up to a point, yes. A larger screen is more immersive, and people rarely wish they had gone smaller. The real limits are your wall, your budget, and sitting so close that you have to turn your head to take in the edges.
Can you really see the difference between 4K and 8K?
Almost never from a normal seat. The pixels on an 8K screen are so small you would have to sit closer to the TV than to your coffee table to resolve them, so for living-room viewing it makes no visible difference.
Once you have a size in mind, check your set is really running 4K with the Screen Resolution Test, see is my TV really 4K, weigh up 4K vs 8K, and read the fuller viewing distance guide.