Convert Light Years to Femtometers
Convert Light Years (ly) to Femtometers (fm) instantly and accurately.
Conversion Formula
fm = ly × 9.460730473e+30
About Light Years
A light year (ly) is the distance light travels in one year through a vacuum, approximately 9.46 trillion kilometers. This is the primary unit for measuring stellar distances. Our nearest star neighbor, Proxima Centauri, is 4.24 light years away, meaning its light takes over 4 years to reach us. The center of our Milky Way galaxy is about 26,000 light years distant, and the nearest large galaxy (Andromeda) is 2.5 million light years away. When we observe distant objects, we're literally seeing them as they were years ago.
About Femtometers
A femtometer (fm) is an incredibly tiny unit equal to one quadrillionth of a meter (10⁻¹⁵ m). To put this in perspective, if an atom were the size of a football field, a femtometer would be the size of a marble. This unit is primarily used in nuclear physics to measure the size of atomic nuclei, protons, and neutrons. The proton, for example, has a diameter of about 1.7 femtometers.
Quick Reference Table
| Light Years (ly) | Femtometers (fm) |
|---|---|
| 1 ly | 9.461 × 1030 fm |
| 2 ly | 1.892 × 1031 fm |
| 5 ly | 4.73 × 1031 fm |
| 10 ly | 9.461 × 1031 fm |
| 25 ly | 2.365 × 1032 fm |
| 50 ly | 4.73 × 1032 fm |
| 100 ly | 9.461 × 1032 fm |