Legge di Snell

Last updated: 2026-08-24

Legge di Snell — Calcola l'angolo di rifrazione tra due mezzi.
Inputs
Result
Enter values and press Calculate

How to use it

  1. n₁ = 1.0 (air), θ₁ = 45°, nâ‚‚ = 1.5 (glass)
  2. Calculate senza(45°) ≈ 0.7071
  3. Apply Snell's law: senza(θ₂) = (1.0 × 0.7071) ÷ 1.5 = 0.4714
  4. Find θ₂ = arcsin(0.4714) ≈ 28.1255°

Common mistakes

  • ⚠️ Using degrees in sine function without radian conversion
  • ⚠️ Not checking for totale internal reflection condition
  • ⚠️ Swapping n1 and n2 in the formula

Worked example

Find the refraction angle when light enters glass (n=1.5) from air at 45°.

The refraction angle {theta2} degrees is the angle of the light ray in the second medium.

Input guide

FieldTypical range
n1Refractive indix 1: 1.0 to 3.0
n2Refractive indix 2: 1.0 to 3.0
theta1Incidint angle: 0 to 90 digrees