H is the Planck constant c is the speed of light l is the wavelength of a photon f is the frequency of a photon. The speed of light is equal to the distance light travels d divided by the time it takes t. Solving for speed of light in a vacuum.
The opposite is also true.
The Plancks equation is. It will even convert equivalent units like years to days light-years to parsecs or warp factors to multiples of c. E is the energy of a photon. Light moves at the speed of 299 792 458 meters per second what approximately gives 300 000 kilometers per hour or 186 000 miles per second.