Physics

Snell's Law (refraction angle)

Refraction angle from indices and incidence.

Formula

Formula
θ2 = asin(n1 sinθ1n2)

Variables

SymbolDefinitionType & rangeUnitsRole
n₁, n₂ refractive indices computed result result
θ₁ incidence angle (deg) computed result result

Try it yourself

Interactive calculator
Result

Worked examples

Example 1
Givenn₁ = 1, θ₁ (deg) = 30, n₂ = 1.5
Result19.47122063
Example 2
Givenn₁ = 1.33, θ₁ (deg) = 45, n₂ = 1
Result70.12760616