**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 1.0570008340246E-16 light years.

Valid units must be of the **length** type.

You can use this form to select from known units:

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 years to pearl

light years to arsheen [Russia]

light years to perch [Ireland]

light years to X unit

light years to gigalight year

light years to cuadra [Argentina]

light years to lug

light years to bohr

light years to ligne [France]

light years to gry