TV Size for Room
How big a TV should you buy for your living room? Enter your seating distance below and the calculator gives you a recommended diagonal range that hits the cinema-grade THX viewing angle without overwhelming the room.
How this calculator works
Three published standards define the ideal viewing distance for a screen of a given diagonal. THX cinema is 1.55× diagonal. SMPTE recommended max is 1.875× diagonal. 4K immersive (only meaningful with 4K source) is 0.84× diagonal. Solve any of these in reverse and you get the diagonal that matches your distance.
For example: if you sit 8 ft (2.4 m) from your TV, dividing by 1.55 gives a 62-inch diagonal — exactly the THX cinema sweet spot. SMPTE pulls that down to about 51 inches; 4K immersive lets you go up to ~114 inches if you have native 4K source.
Quick reference: TV size by viewing distance
- 6 ft (1.8 m): 38-46 inch sweet spot. A 43-inch TV is the most common pick for bedrooms or small living rooms.
- 8 ft (2.4 m): 51-62 inch sweet spot. The 55-65 inch range covers most living rooms.
- 10 ft (3.0 m): 64-77 inch sweet spot. 65-75 inch TVs hit the THX cinema target.
- 12 ft (3.6 m): 77-93 inch sweet spot. Projector-screen territory for dedicated home theaters.
Frequently asked questions
Is bigger always better?
No. Past the SMPTE distance you stop perceiving the screen as cinematic — it just feels far away. Past the 4K immersive multiplier you'll start seeing individual pixels on lower-resolution content, and head movement becomes tiring.
Does the TV's resolution matter?
Yes. The 4K immersive multiplier (0.84× diagonal) only works with native 4K source — at that distance, a 1080p TV reveals visible pixels. Stick to THX (1.55×) or SMPTE (1.875×) for mixed content.
What if my room is asymmetric?
Measure to your most-used seating position (usually the center of the couch). Side seats accept smaller TVs comfortably; the THX standard assumes you're seated near center.