Convert millimeters (mm) to light years (ly) with formulas, examples, and conversion tables.
How to Convert millimeters to light years
To convert millimeters to light years, divide the value by 9.461e18.
The Formula
light years = millimeters ÷ 9.461e18
Key Fact
1 light year = 9.461e18 millimeters
Tip: To convert light years back to millimeters, multiply by 9.461e18.
About Millimeters and Light Years
What is a Millimeter?
The millimeter (mm) is a unit of length in the metric system. One millimeter equals 0.001 meters.
What is a Light Year?
The light year (ly) is a unit of length in the astronomical system. One light year equals 9461000000000000 meters.