›› Measurement unit: light year

Full name: light year

Plural form: light years

Symbol: ly

Alternate spelling: lightyear

Category type: length

Scale factor: 9460730472580800


›› SI unit: metre

The SI base unit for length is the metre.
1 metre is equal to 1.0570008340246E-16 light year.


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›› Definition: Light-year

A light year, abbreviated ly, is the distance light travels in one year: roughly 9.46 × 1012 kilometres (9.46 petametres, or about 5.88 × 1012 (nearly six trillion) miles). More specifically, a light year is defined as the distance that a photon would travel, in free space and infinitely far away from any gravitational or magnetic fields, in one Julian year (365.25 days of 86400 seconds each).


›› Sample conversions: light year

light year to foot [Netherlands]
light year to cape foot
light year to ken [Japan]
light year to hectometre
light year to gnat's eye
light year to bicron
light year to mile
light year to pie [Spanish]
light year to li [ancient China]
light year to light day