TV Size & Distance Calculator

Viewing Angle Standards

The calculator uses established home theater standards to determine the ideal relationship between screen size and viewing distance:

• THX Recommendation: A 40° viewing angle for a cinematic experience. This is the primary recommendation used by this calculator.
• SMPTE (Society of Motion Picture & Television Engineers): A 30° minimum viewing angle for a good experience.
• Casual Viewing: A wider range allowing smaller angles (around 20°), suitable for general TV watching.

The Math

The relationship between TV size, distance, and viewing angle is:

1. Screen width = diagonal × cos(arctan(9/16)) ≈ diagonal × 0.871
2. Viewing angle = 2 × arctan(screen width / (2 × distance))
3. Ideal distance = screen width / (2 × tan(angle / 2))

Resolution Matters

Higher-resolution TVs let you sit closer without seeing individual pixels:

• 1080p: Best at 1.5–2.5× the screen diagonal distance
• 4K: Best at 1.0–1.5× the screen diagonal distance
• 8K: Best at 0.75–1.0× the screen diagonal distance

Tips

• TV screen sizes are measured diagonally corner to corner
• For mixed use (movies, sports, gaming), the THX 40° angle is a good target
• Mount the TV so the center of the screen is at seated eye level
• If your room constrains your distance, a 4K or 8K TV lets you sit closer comfortably