Distance units based on the speed of light

Unit	Definition	Distance			Example
		m	km	miles
light-second		2.997924580×108 m	2.998×105 km	1.863×105 miles	average distance from the Earth to the Moon is about 1.282 light-seconds
light-minute	60 light-seconds	1.798754748×1010 m	1.799×107 km	1.118×107 miles	average distance from the Earth to the Sun is 8.317 light-minutes
light-hour	60 light-minutes = 3600 light-seconds	1.079252849×1012 m	1.079×109 km	6.706×108 miles	semi-major axis of Pluto's orbit is about 5.473 light-hours
light-day	24 light-hours = 86400 light-seconds	2.590206837×1013 m	2.590×1010 km	1.609×1010 miles	Sedna is currently 0.52 light-days from the Sun
light-week	7 light-days = 604800 light-seconds	1.813144786×1014 m	1.813×1011 km	1.127×1011 miles	The Oort cloud is thought to extend between 41 and 82 light-weeks out from the Sun
light-year	365.25 light-days = 31557600 light-seconds	9.460730473×1015 m	9.461×1012 km	5.879×1012 miles	Proxima Centauri is the nearest star to the Sun, about 4.24 light-years away