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Projector Lumens Calculator
Required brightness based on screen size and room conditions
Inputs
Select Unit
fL
×
Results
Required Lumens
4,500Lm
Screen Area
56.25ft²
Image Width
10.00 ft
Image Height
5.63 ft
Diagonal
11.47 ft
Screen Gain
1.0×
References
Image Height = Width ÷ Aspect (16:9) = 10.00 ÷ 1.7778 = 5.63 ft
Diagonal = √(Width² + Height²) = √(10.00² + 5.63²) = 11.47 ft
Screen Area = Width × Height = 10.00 × 5.63 = 56.25 ft²
Required Lumens = (Brightness × Area) ÷ Gain = (80 × 56.3 ft²) ÷ 1 = 4,500 Lm
Required Lumens is always computed from the area in ft² — the foot-lambert brightness formula is defined per square foot, regardless of the unit selected for display above.
Brightness Guide: 20–30 fL dark rooms | 40–60 fL ambient light | 80+ fL bright rooms
Screen Gain: 1.0 = matte white | 1.3+ = high gain | 0.8 = ALR