18 lightyears equals 1,138,339.39 astronomical units.
Convert 18 lightyears into meters, kilometers, decimeters, centimeters, milimeters, micrometers, nanometers, picometers, inches, feet, yards, miles, hands, parsecs, etc...
Convert 1138340 astronomical units into meters, kilometers, decimeters, centimeters, milimeters, micrometers, nanometers, picometers, inches, feet, yards, miles, hands, parsecs, etc...