TV Size Calculator
What size TV should you buy?
Enter your viewing distance and get the ideal TV size based on THX and SMPTE viewing angle standards, plus every common size compared.
How it works
The math behind the answer
The right TV size is a function of how far away you sit and how much of your field of view the screen should fill. Film standards express this as a viewing angle: SMPTE recommends at least 30° for a cinematic experience, and THX recommends 36°, with 40° the figure most often quoted as the immersive maximum.
The calculator converts your distance and a target angle into a 16:9 screen width, then into the diagonal you see on the box. It also shows what every common retail size would look like from your seat, and how far you can sit before 4K detail stops being visible to a viewer with 20/20 vision.
Most people end up buying a TV that is smaller than these standards suggest. If you are torn between two sizes and the room supports it, the larger one is almost always the right call.
Common questions
- Is a 65 inch TV too big for 8 feet away?
- No. At 8 feet a 65 inch 16:9 TV fills about 33° of your view, right in the SMPTE-to-THX sweet spot for mixed movie and TV use.
- How far should you sit from a 75 inch TV?
- For a cinematic feel, about 7.5 to 8.5 feet (36 to 40°). For comfortable everyday viewing, up to about 10 feet (SMPTE 30°).
- Does 4K change the ideal size?
- Resolution does not change the ideal viewing angle, but it changes how close you can sit before you see pixels. 4K lets you sit at THX distances without visible pixel structure; 1080p needed roughly double the distance.