🛋️ TV Size to Room Size Calculator
Enter your available seating-to-wall distance and resolution to see the recommended TV diagonal size range for that room.
Working backwards from the distance you have
Your seat is already where it is, so the diagonal is solved for instead:
diagonal (in) = viewing distance in inches / multiplier
4K: 1.0 - 1.5 (mid 1.2)
1080p: 1.5 - 2.5 (mid 2.0)
720p: 2.5 - 3.5 (mid 3.0)Note the multipliers invert, so the smallest size comes from the largest one. At the default 9 ft, which is 108 in, a 4K set works out as:
| Result | Diagonal | Viewing angle |
|---|---|---|
| Largest | 108 in | 47° |
| Ideal | 90 in | 40°, the THX target |
| Smallest | 72 in | 32° |
SMPTE's more conservative 30° would call for 66 in, just under the smallest figure returned. Switch to 1080p and the ideal drops to 54 in, because pixel structure becomes visible before the angle does.
Checking the answer fits the wall
- Round to a size that exists. Panels come at 55, 65, 75, 85 and 98 in, so the 90 in answer means an 85 in set.
- Measure the cabinet, not just the wall. A 90 in 16:9 screen is 78 in wide and 44 in tall before the bezel and any stand feet.
- Set the height by the seat. Screen centre near seated eye level, roughly 42 in from the floor, matters more than the size you chose.
Frequently asked questions
What size TV do I need for a 9 foot viewing distance?
For 4K, 90 in is the ideal figure, with 72 in to 108 in as the usable range. In practice that means buying an 85 in set, the nearest size actually sold.
Is a 75 inch TV too big for a small living room?
Rarely. A 75 in 4K screen only passes the closest recommended limit under about 6.25 ft, and at a typical 8 ft sofa distance the ideal is 80 in.
Why does this suggest a bigger TV than I expected?
Because it targets the angle a cinema seat gives. The 4K band assumes you cannot see pixel structure at that range - true of 4K, but not of the 1080p sets these habits were formed on.