Instant · Precise · Universal
32 units available
6 categories total
To convert ly to km: multiply by 9.461 × 10¹². To convert ly to parsecs: multiply by 0.3066.
1 ly = 9.4607 × 10¹⁵ m = 63,241 AU = 0.3066 pc ≈ 9.461 trillion km.
For example, 1 Light Year (ly) = 13586322.77 Sun's Radius (R☉).
| Light Year (ly) | Sun's Radius (R☉) |
|---|---|
| 0.1 | 1358632.277 |
| 0.5 | 6793161.387 |
| 1 | 13586322.77 |
| 2 | 27172645.55 |
| 5 | 67931613.87 |
| 10 | 135863227.7 |
| 25 | 339658069.3 |
| 50 | 679316138.7 |
| 100 | 1358632277 |
| 500 | 6793161387 |
| 1000 | 13586322770 |
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.
The solar radius is the radius of the Sun, approximately 6.9634 × 10⁸ meters (about 696,340 km).
1 R☉ = 6.9634 × 10⁸ m = 696,340 km ≈ 109 × Earth's radius ≈ 0.00465 AU.
To convert solar radii to km: multiply by 696,340. To convert solar radii to AU: multiply by 0.00465.
Describing stellar sizes: Betelgeuse ≈ 700 R☉, Sirius ≈ 1.7 R☉, a white dwarf ≈ 0.01 R☉.
You could line up about 109 Earths across the Sun's diameter. The largest known star (UY Scuti) is about 1,700 R☉.
Confusing solar radius with solar diameter — the diameter is 2 R☉. Also, stellar catalogs list radius, not diameter.
The Sun's radius (109 × Earth) gives a sense of scale: you could fit over a million Earths inside the Sun by volume.



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