Snell's Law Calculator – Refraction Calculator
Calculate the angle of refraction using Snell's law. Our calculator also determines the critical angle for total internal reflection.
How Snell's Law Works
1
Enter Refractive Indices
Input n₁ and n₂ for the two media or select from presets.
2
Set Incident Angle
Enter the angle at which light hits the boundary.
3
Calculate Refraction
Get the refraction angle or critical angle instantly.
Snell's Law Formula
n₁ × sin(θ₁) = n₂ × sin(θ₂)
Where n = refractive index, θ = angle from normal
Refractive Indices of Common Materials
Air: 1.0003
Water: 1.333
Crown Glass: 1.52
Flint Glass: 1.62
Diamond: 2.42
Sapphire: 1.77
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