Physics
Index of Refraction Calculator
Find a medium's refractive index from light speed.
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The refractive index shows how much a material slows light.
The math behind it
n = speed of light in vacuum (299,792,458 m/s) ÷ speed in the medium.
Worked Example
2.25 × 10⁸ m/s → n ≈ 1.33 (water).
Frequently Asked Questions
Higher n?
Light travels slower and bends more.
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