About This Refractive Index Calculator
Refractive index is a dimensionless ratio that describes how much light slows down in a material. This calculator compares two media and applies Snell's Law to estimate bending at their boundary.
How to use it
Choose the starting and destination material, enter the incident angle, and review the relative refractive index, speed ratio, refracted angle, and critical angle. Use Custom when you have a measured material index.
Materials covered
The presets include vacuum, air, water, ethanol, acrylic, crown glass, flint glass, sapphire, and diamond. Values are typical references and can vary with wavelength, temperature, and material composition.