Dog From The Moon · Free production tool
Beam Divergence & Spot Size

Estimate laser beam divergence and spot size at throw so designers know whether graphics will still read from FOH.

Calculate laser beam divergence and spot size for show design and safety planning.

  • Predict spot size at real throw
  • Compare optics before locking content
  • Pair with scan-angle planning

Beam Divergence & Spot Size

Compute spot diameter versus distance. Supports full or half-angle and mrad or degrees.

Inputs

Most manufacturers publish full-angle mrad. If you only have half-angle, pick “Half-angle” and enter that value.

Results

Distance (m)
20
Full angle (rad)
0.0012
Spot diameter (mm)
27
Spot diameter (in)
1.063
Spot area (m²)
0.0006
This is a geometric estimate. It does not assess eye safety or MPE. Use certified methods for audience scanning evaluations.

Quick look: common distances

Distance (m)Spot dia (mm)
1015
2027
4051
6075
100123