Illumination Calculators

Always use the same units (inches or mm) in each calculation (unless indicated).
Enter your numbers into the yellow cells. To recalculate, press the TAB key, or click in another yellow box, or
\click the Update button. Other formulas you’d like to see?

Note: Turn phone horizontal for best results.

Illumination Circle Size Bundle Dia. Fiber NA Distance Circle Size    
NA = Sin of Half Angle = Numerical Aperture is an angle measurement and is specified by the fiber manufacturer.    
Size of a Collimated Beam NA Bundle Dia. Lens Focal Length Beam Dia. at Focal Length Diver-gence Full Angle (radians) Diver-gence Full Angle (degrees) Distance From Lens Focus Beam Dia. at Distance    
Convert Feet Feet Inches mm Meters    
Convert mm mm Inches Feet Microns    
Convert meters Meters Feet Inches mm