Speed of Light Calculator

Free calculate speed of light in vacuum, air, water, and other media. convert light speed between units and calculate using refractive index.

Input Parameters

Results

Select medium to calculate speed of light

Speed of Light Formula

Formula

v = c / n

Where:

  • • v = speed in medium (m/s)
  • • c = speed in vacuum (299,792,458 m/s)
  • • n = refractive index

Common Values

  • • Vacuum: 299,792,458 m/s
  • • Air: ~299,700,000 m/s
  • • Water: ~225,000,000 m/s
  • • Glass: ~200,000,000 m/s
  • • Diamond: ~124,000,000 m/s

Related Physics Calculators

Explore more calculators in this category:

Browse all Physics Calculators →