Light Travel Calculator

Light is the fastest thing there is, and space is huge. See how long light, a jet, a car or a spacecraft would need to reach somewhere.

Destination

Or enter a distance

Unit

Notes

Light travels 299,792 km every second, about 7.5 times around Earth. A light-year is the distance light covers in a year, about 9.46 trillion km. Distances to planets change as they orbit, so those entries use the closest approach to Earth. Spacecraft speeds are record or typical values: Apollo 10 reached about 39,900 km/h (the crewed record), Voyager 1 moves at about 17 km/s relative to the Sun, and Parker Solar Probe has reached about 692,000 km/h.