Convert Light Years (ly) into other units of length e.g. m, cm, km, ft, in, μm, mm, mi, yd

You are: Home > Length > Light Years

Let's convert Light Years (ly) to another unit of Length

This quick and easy calculator will convert Light Years (ly) into other units of length e.g. m, cm, km, ft, in, μm, mm, mi, yd

Choose a unit to convert Light Years into:

Common
Centimeters
(cm)
Common
Feet
(ft)
Common
Inches
(in)
Common
Kilometres
(km)
Common
Metres
(m)
Common
Micrometres
(μm)
Common
Miles
(mi)
Common
Millimetres
(mm)
Common
Yards
(yd)
Angstroms
(Å)
Astronomical Units
(AU)
Calibers
(cl)
Ells
(ell)
Ems
(em)
Fathoms
(ftm)
Fermis
(fm)
Furlongs
(fur)
Leagues
(leagues)
Mils
(mil)
Nanometres
(nm)
Parsecs
(pc)
Picas
(pc)
Picometres
(pm)
Points
(pt)
Rods
(rod)

Unit Information

Light Year
/lʌɪt jɪə,jəː/
Symbol: ly
Unit System: Astronomical System of Units

What is the Light Year?

The light year is a unit of length in the Astronomical system of units. It uses the symbol ly.

Often confused with a unit of time as it contains the word "year", it is actually defined by the International Astronomical Union (IAU) as the amount of distance that light travels in a vacuum in one Julian year (365.25 days).

Using the speed of light (299,792,458 m/s or 'c') and the Julian year (as apposed to the Gregorian year which is 365.2425 days), we can equivalate 1 light year as 9,460,730,472,580,800 metres or ≈ 9.46 trillion kilometres.