Calculate TIR (Total Internal Reflection) lens specifications — efficiency, critical angle, Fresnel losses, lens diameter, and working distance for any LED source size and target beam angle. Compare TIR lens efficiency against traditional reflectors and select the right lens material for your application.
Measurement units
Metric
Millimetres (mm)
Imperial
Inches (in)
Lens material
PMMA (Acrylic)
n = 1.49
PC (Polycarbonate)
n = 1.58
Silicone
n = 1.41
Borosilicate glass
n = 1.47
LED source specification
Physical footprint — lens must clear this
Affects material selection and bulk absorption
Target beam specification
Distance from LED surface to lens exit face
Please fill in required fields.
TIR lens optical efficiency
0%
0mm
Lens diameter
0mm
Focal length
0°
Critical angle
0 lm
Delivered lumens
TIR lens cross-section — ray path through lens
Lens specification output
Optical loss breakdown
Material comparison — same beam angle and working distance
MaterialnCrit. angleEfficiencyDelivered lm
TIR lens design and selection tips
Material
Refractive index (n)
Critical angle
Fresnel loss (entry + exit)
Bulk absorption loss
Total optical efficiency
vs equivalent reflector
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