Instant · Precise · Universal
32 units available
6 categories total
For example, 1 Petameter (Pm) = 0.1057004239 Light Year (ly).
| Petameter (Pm) | Light Year (ly) |
|---|---|
| 0.1 | 0.01057004239 |
| 0.5 | 0.05285021193 |
| 1 | 0.1057004239 |
| 2 | 0.2114008477 |
| 5 | 0.5285021193 |
| 10 | 1.057004239 |
| 25 | 2.642510596 |
| 50 | 5.285021193 |
| 100 | 10.57004239 |
| 500 | 52.85021193 |
| 1000 | 105.7004239 |
The light-year is the distance that light travels in one Julian year (365.25 days) in a vacuum, approximately 9.461 × 10¹⁵ meters.
1 ly = 9.4607 × 10¹⁵ m = 63,241 AU = 0.3066 pc ≈ 9.461 trillion km.
To convert ly to km: multiply by 9.461 × 10¹². To convert ly to parsecs: multiply by 0.3066.
Expressing distances to stars: Proxima Centauri ≈ 4.24 ly, Sirius ≈ 8.6 ly, Vega ≈ 25 ly.
When you see a star 100 light-years away, you're seeing it as it was 100 years ago — you're literally looking into the past.
Thinking a light-year is a unit of time — it's a unit of distance! It's how far light travels in one year.
Light speed = ~300,000 km/s. In one year, light covers ~9.46 trillion km. That distance is one light-year.



© 2026 UntangleTools. All Rights Reserved.