Refractive Index Calculator

Summary

The refractive index (n) of a medium describes how much slower light travels through it compared to a vacuum. It is defined as n = c / v, where c is the speed of light in vacuum (299,792,458 m/s) and v is the phase velocity of light in the medium. This calculator lets you compute n from v, or solve for v given n. It also displays the wavelength compression factor and the critical angle for total internal reflection.

How it works

1. Choose a calculation mode: find the refractive index n, or find the speed of light v.
2. Enter the known value (speed of light in the medium, or refractive index).
3. Click Calculate to see the result instantly.
4. The tool applies the formula n = c / v using c = 299,792,458 m/s.
5. Results include the refractive index, phase velocity, wavelength factor, and critical angle.

Use cases

• Physics and optics homework involving Snell's law.
• Verifying refractive indices for glass, water, diamond, or other materials.
• Computing the phase velocity of light in fiber optic cables.
• Finding the critical angle for total internal reflection.
• Teaching or learning the relationship between speed of light and optical density.
• Engineering calculations for lens and prism design.

Frequently Asked Questions