Home › Calculators › Waves & Optics › Refractive Index Calculator
Refractive Index Calculator
Find a material's refractive index from the speed of light inside it, or the light speed inside a material of known index.
n = c ÷ v
The refractive index is how many times slower light travels in a material than in a vacuum.
Refractive index
—
The calculation runs entirely in your browser — no data leaves your device. Change any number and the answer updates instantly.