Enter the wavelength (m) and the diameter (m) into the Calculator. The calculator will evaluate the Beamwidth. 

Beamwidth Formula

BW = 70*WL/D


  • BW is the Beamwidth (m)
  • WL is the wavelength (m)
  • D is the diameter (m)

To calculate Beamwidth, divide the wavelength by the diameter, then multiply by 70.

How to Calculate Beamwidth?

The following steps outline how to calculate the Beamwidth.

  • First, determine the wavelength (m). 
  • Next, determine the diameter (m). 
  • Next, gather the formula from above = BW = 70*WL/D.
  • Finally, calculate the Beamwidth.
  • After inserting the variables and calculating the result, check your answer with the calculator above.

Example Problem : 

Use the following variables as an example problem to test your knowledge.

wavelength (m) = 1238

diameter (m) = 512