Snell's Law Calculator
Calculate refraction angles using Snell's law of refraction
About this calculator
The Snell's Law Calculator determines refraction angles when light passes between different media with varying refractive indices. This essential physics tool applies Snell's law (n₁sinθ₁ = n₂sinθ₂) to calculate how light bends at material boundaries. It's invaluable for students studying optics, engineers designing optical systems, and professionals working with lenses, prisms, or fiber optics. The calculator helps predict light behavior in applications ranging from eyeglass design to underwater photography corrections.
How to use
Enter the refractive indices of both materials (n₁ and n₂) and the incident angle (θ₁) in degrees. The calculator will automatically compute the refraction angle (θ₂) using Snell's law. Ensure your incident angle doesn't exceed the critical angle to avoid total internal reflection scenarios.
Frequently asked questions
What is Snell's law and when is it used?
Snell's law describes how light bends when crossing boundaries between materials with different refractive indices, essential for optics and wave physics applications.
What happens at the critical angle?
At the critical angle, light undergoes total internal reflection instead of refraction, meaning no light passes through to the second medium.
What are common refractive index values?
Air: 1.00, Water: 1.33, Glass: 1.5-1.9, Diamond: 2.42. These values determine how much light bends when entering different materials.