Beam Geometry

Beam Angle and Beam Spread Calculator

Estimate beam diameter, coverage width, and coverage area at a throw distance.

Lighting calculator Beam Geometry Updated August 26, 2026

Inputs

Results

Beam diameter -- m
Coverage width -- m
Coverage area -- m2
Calculation details
Beam diameter
-- m
Coverage width
-- m
Coverage area
-- m2
Important notes
  • Use the manufacturer beam-angle definition and target-plane convention.
  • Australian standards may inform planning boundaries; this result is not an automatic compliance declaration.

Formulas

  • \(\displaystyle D = 2d\tan(\theta/2)\)
  • \(\displaystyle A = \pi(D/2)^2\)
  • Geometry only; beam intensity and uniformity require product photometry.

Estimate beam diameter, coverage width, and coverage area at a throw distance.

Beam Angle and Beam Spread Calculator is a planning aid. Keep the target source, product data, measurement method, and project assumptions with the result. Confirm compliance, installation, certification, and safety decisions with the responsible professional.