📺TV Size Calculator
Tell us how far your couch is from the screen and we'll suggest the TV size range that looks best.
Your setup
Best screen size
66–90 inches
66″ to 90″ diagonal for a 30°–40° viewing angle
minimum (30°)
66″
maximum
90″
distance
9.0 ft
4K lets you go bigger — 40° is the cinema-style sweet spot.
How it works
A 16:9 screen fills your view nicely between a 30° and 40° viewing angle (SMPTE and THX guidelines).
- Screen width = 2 × distance × tan(angle ÷ 2)
- Diagonal = width ÷ 0.872
For 1080p we cap the top of the range at distance ÷ 1.6 so pixels don't become visible.
Worked example
9 ft (108 in) away with a 4K TV:
- 30°: 2 × 108 × tan 15° ÷ 0.872 = 66 in
- 40°: 2 × 108 × tan 20° ÷ 0.872 = 90 in
- So a 65–85 inch TV is a great pick.
Questions people ask
About 59–80 inches for 4K, using the 30°–40° viewing angle rule.
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Last updated October 8, 2026. These results are friendly estimates to help you plan — always double-check before buying or making big decisions.