How fast is light in kilometers per hour?

The speed of light is 2.99793x108 m/s, which, when multiplied by the number of seconds in an hour (3600) and divided by the number of metres in a km comes to 1,079,254,800 km / hr - a little under the closest that the Planet Saturn approaches the Earth.

A more interesting way to remember the speed of light is to recall that it is approximately 1 foot per nanosecond.