Snell's Law Calculator
( Refractive Index Calculator)

1st Medium Refraction Indices:
Angle of Incidence:
2nd Medium Refraction Indices:
Angle of Transmission:

Snell's law describes a ray refracts at an interface between materials. Snell's Law formula:
n1sinθ1 = n2sinθ2

where:

n1: Indices of refraction of Medium 1, dimensionless
θ: Angle of incidence, in radian
n2: Indices of refraction of Medium 2, dimensionless
θ: Angle of transimission, in radian

Refractive Index Chart of Common Materials:
Material
Condition
Refractive Index
Vacuum

1 (per definition)
Air at standard atmosphere

1.000277
Air
Gas at 0 ̊C, 1 atmosphere
1.000293
Helium
Gas at 0 ̊C, 1 atmosphere
1.000036
Hydrogen
Gas at 0 ̊C, 1 atmosphere
1.000132
Carbon dioxide
Gas at 0 ̊C, 1 atmosphere
1.00045
Benzene
Liquid at 20 ̊C
1.501
Carbon disulfide
Liquid at 20 ̊C
1.628
Carbon tetrachloride
Liquid at 20 ̊C
1.461
Ethanol
Liquid at 20 ̊C
1.361
Silicone oil
Liquid at 20 ̊C
1.52045
Water
Liquid at 20 ̊C
1.3330
Titanium dioxide
Solid at room temperature
2.496
Diamond
Solid at room temperature
2.419
Strontium titanate
Solid at room temperature
2.41
Amber
Solid at room temperature
1.55
Fused silica
Solid at room temperature
1.458
Sodium chloride
Solid at room temperature
1.50
Water ice

1.31
Cornea (human)

1.3375
Cryolite

1.338
Acetone

1.36
Ethanol

1.36
Polytetrafluoroethylene

1.35 - 1.38
Lens (anatomy) (human)

1.386 - 1.406
Sylgard 184

1.43
Pyrex

1.470
Glycerol

1.4729
Acrylic glass

1.490 - 1.492
Halite

1.516
Crown glass (optics)

1.50 - 1.54
Polycarbonate

1.584 - 1.586
Poly(methyl methacrylate)

1.4893 - 1.4899
PETg

1.57
Polyethylene terephthalate (PET)

1.5750
Flint glass (pure)

1.60 - 1.62
Crown glass (impure)

1.485 - 1.755
Bromine

1.661
Sapphire

1.762 - 1.778
Flint glass (impure)

1.523 - 1.925
Cubic zirconia

2.15 - 2.18
Potassium Niobate (KNbO3)

2.28
Moissanite

2.65 - 2.69
Cinnabar (Mercury sulfide)

3.02
Gallium(III) phosphide

3.5
Gallium(III) arsenide

3.927
Zinc Oxide

2.4
Silicon

4.01