Projector viewing distance calculator
Enter your screen size to get the recommended seating distance by the THX (36°) and SMPTE (30°) standards. Free calculator with a size-to-distance reference table.
For a 100-inch 16:9 screen, sit about 11.2 ft away for the immersive THX standard (36° field of view) and about 13.6 ft for the more relaxed SMPTE standard (30°). Closer feels cinematic; farther is easier on the eyes. Enter your size below.
Seating distance by screen size
| Screen | THX (36°) | SMPTE (30°) |
|---|---|---|
| 80″ | 8.9 ft | 10.8 ft |
| 100″ | 11.2 ft | 13.6 ft |
| 120″ | 13.4 ft | 16.3 ft |
| 150″ | 16.8 ft | 20.3 ft |
| 200″ | 22.4 ft | 27.1 ft |
How viewing distance is calculated
The recommended distance comes from the horizontal field of view the screen fills at your seat: distance = (image width ÷ 2) ÷ tan(angle ÷ 2). THX targets a 36° field of view for an immersive cinema feel, while SMPTE targets 30° for a more relaxed image — so the THX distance is always closer than the SMPTE one. Anywhere between the two is a comfortable range; sit closer for movies, farther for all-day or mixed use.
Not sure what screen size fits? Use the screen size calculator. →
Find your seating distance
11.2 ft
THX (36° — immersive)
13.6 ft
SMPTE (30° — relaxed)
Sit between the two for a comfortable mixed-use distance.
Frequently asked questions
Updated