**Full name:** light year

**Plural form:** light years

**Symbol:** ly

**Alternate spelling:** lightyear

**Category type:** length

**Scale factor:** 9460730472580800

The SI base unit for length is the metre.

1 metre is equal to 1.05700083402E-16 light year.

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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).

light year to city block [East U.S.]

light year to pulgada

light year to myriametre

light year to yottametre

light year to miglio

light year to shaftment [ancient]

light year to military pace [double time]

light year to tu

light year to quarter