Angle of Incidence Calculator

Calculate θ₁ from n₁, n₂, and θ₂

How to Use This Calculator

  1. Enter n₁ and n₂ for the two media.
  2. Enter the angle of refraction θ₂ in degrees.
  3. Click Calculate to find θ₁, the angle of incidence.

Formula

n₁sin(θ₁) = n₂sin(θ₂)

θ₁ = arcsin((n₂sin(θ₂))/n₁)

Frequently Asked Questions

What are typical refractive indices?

Air ≈ 1.0, water ≈ 1.33, glass ≈ 1.5, diamond ≈ 2.42.