Beam Angle Calculator
Calculate the beam spread, coverage area, and throw distance for spotlights, downlights, and other directional lighting.
1Light Parameters
Height from light to illuminated surface
2Calculated Results
5.2 ft
Beam Diameter
Coverage Area
21.2 ft²
Beam Radius
2.6 ft
Light Beam Visualization
5.2 ft
diameter
36.0°
8.0 ft
Common Beam Angles
Narrow Spot
Accent lighting, art displays
Spot
Task lighting, product displays
Narrow Flood
General downlighting
Flood
Wide area coverage
Wide Flood
Wall washing, ambient lighting
Very Wide
Ceiling-mounted ambient
What is Beam Angle?
Beam angle is the angle at which light is emitted from a fixture. It determines how concentrated or spread out the light will be. Narrow beam angles (10-25°) create focused spotlights, while wide angles (60-120°) provide broad, ambient illumination.
The Beam Angle Formula
Diameter = 2 × Distance × tan(Angle ÷ 2)
This trigonometric formula calculates the beam diameter based on the throw distance and beam angle. Our calculator handles all the math automatically.
Tips for Choosing Beam Angle
- •Use narrow angles (10-25°) for accent lighting, highlighting art, or task lighting
- •Use medium angles (36-45°) for general downlighting and recessed fixtures
- •Use wide angles (60-120°) for ambient lighting and even room coverage