Use this calculator to get the size and location of your Gaussian laser beam waist at focus, as well as the Rayleigh range.
Also try our Laser Focusability Calculator for a simpler calculator version.

Notes:
- Some of the input parameters are mutually dependent and the software will calculate them automatically when possible. A calculated parameter will be locked for editing. If you wish to unlock it, you must erase the value entered which caused it to be locked. Example: Fields A and B are mutually dependent. You enter a value in A and B is calculated and locked. You wish now to edit B. You must first delete A, upon which B will be erased an unlocked.
- This calculator uses Sidney Self’s equations for focusing spherical Gaussian beams.
- Want to measure the actual beam size? Try a BeamTrack Power/Position/Size sensor, or a full-fledged beam profiler for a complete picture of your laser beam.
Calculated Results
zᵣ Rayleigh Length
:
mm
s" Distance from lens to "new" Waist
:
mm
d₀" New Beam Waist Diameter (After lens)
:
mm
zᵣ" New Rayleigh Length
:
mm
