Light-year (ly)
The distance light travels in one Julian year.
Result
1 light-year = 9.460730473 × 10¹⁸ millimeters
Light-year at a glance
| Unit name | Light-year (plural: light-years) |
|---|---|
| Symbol | ly |
| Quantity measured | Length |
| Measurement system | Other |
| Also known as | lightyear, light year, ly |
| Definition exact? | Yes — exact by definition |
1 light-year in other length units
| Unit | 1 ly equals |
|---|---|
| Nanometer | 9.46073047 × 10²⁴ nm |
| Micrometer | 9.46073047 × 10²¹ µm |
| Millimeter | 9.46073047 × 10¹⁸ mm |
| Centimeter | 9.46073047 × 10¹⁷ cm |
| Decimeter | 9.46073047 × 10¹⁶ dm |
| Meter | 9.46073047 × 10¹⁵ m |
| Kilometer | 9,460,730,472,581 km |
| Inch | 3.72469704 × 10¹⁷ in |
| Foot | 3.1039142 × 10¹⁶ ft |
| Yard | 1.03463807 × 10¹⁶ yd |
| Mile | 5,878,625,373,184 mi |
| Nautical mile | 5,108,385,784,331 nmi |
| Angstrom | 9.46073047 × 10²⁵ Å |
| Mil | 3.72469704 × 10²⁰ mil |
| Fathom | 5.17319033 × 10¹⁵ ftm |
| Rod | 1.88116012 × 10¹⁵ rd |
| Chain | 470,290,029,854,689 ch |
| Furlong | 47,029,002,985,469 fur |
| League | 1,959,541,791,061 lea |
| Astronomical unit | 63,241.0771 au |
| Parsec | 0.306601394 pc |
Frequently asked questions
- What is a light-year?
- The distance light travels in one Julian year.
- What is the symbol for the light-year?
- The symbol for the light-year is ly. It measures length.
- How many millimeters are in a light-year?
- 1 light-year = 9.46073047 × 10¹⁸ millimeters.
- How many centimeters are in a light-year?
- 1 light-year = 9.46073047 × 10¹⁷ centimeters.
- How many meters are in a light-year?
- 1 light-year = 9.46073047 × 10¹⁵ meters.