How Fast Does Light Travel In 1 Nanosecond?

How Fast Does Light Travel In 1 Nanosecond? Summary. The speed of light in a vacuum is the same constant in all inertial (i.e. non-accelerating) frames of reference. Light travels approximately 1 foot per nanosecond or 186 miles per millisecond or 300,000 kilometers per second. How fast does light travel per second? The speed of