Lighting
Light Beam Diameter Calculator
Light Beam Diameter reports beam diameter from one operating case.
Enter values for beam diameter
Use one consistent electrical operating case for all fields.
How Light Beam Diameter works
The calculation uses diameter = 2d tan(angle/2). Light Beam Diameter uses Throw distance, Beam-angle tangent factor to report Beam diameter.
With the loaded values, beam diameter evaluates to 2.68 m. Keep other entries fixed when exploring a measurement range. Use Inverse Square Lighting Calculator.
Inputs for Light Beam Diameter
Throw distance and Beam-angle tangent factor belong to Light Beam Diameter. Keep source units with throw distance.
The opening values are placeholders for testing the arithmetic. Compare this result with Lumen Depreciation Calculator when maintained lumens is also needed.
- Throw distance
- Example entry: 5 m.
- Beam-angle tangent factor
- Example entry: 0.536.
Reading the Light Beam Diameter result
This output represents Light Beam Diameter.
Do not treat the calculated number as a component rating by itself. Check standard sizes, transients, protective margins, and manufacturer limits.
Measurement and units
Photometric results depend on fixture distribution, reflectance, mounting, maintenance, and the measured task plane. Check prefixes on throw distance. For circuit current, use Lighting Circuit Current Calculator.
Use the same unit basis and observation location in alternate cases.
Limits of this calculation
Manufacturer beam angle definitions can differ. Continue to Occupancy Sensor Savings Calculator for annual energy saved.
This equation represents one relationship rather than a full circuit simulation. Unentered effects remain outside Light Beam Diameter.
Questions about Light Beam Diameter
What does Light Beam Diameter calculate?
Light Beam Diameter reports beam diameter.
Can Throw distance be zero?
For Light Beam Diameter, measure any zero throw distance directly.
Why can beam diameter differ from measurement?
Manufacturer beam angle definitions can differ. Recheck throw distance.
Should the result be rounded?
Keep extra digits while comparing cases, then round to the precision supported by throw distance.