Instant · Precise · Universal
32 units available
6 categories total
To convert Mm to km: multiply by 1,000. To convert Mm to miles: multiply by 621.371.
1 Mm = 10⁶ m = 1,000 km = 1,000,000 m.
For example, 1 Megameter (Mm) = 1.057004e-10 Light Year (ly).
| Megameter (Mm) | Light Year (ly) |
|---|---|
| 0.1 | 1.057004e-11 |
| 0.5 | 5.285021e-11 |
| 1 | 1.057004e-10 |
| 2 | 2.114008e-10 |
| 5 | 5.285021e-10 |
| 10 | 1.057004e-9 |
| 25 | 2.642511e-9 |
| 50 | 5.285021e-9 |
| 100 | 1.057004e-8 |
| 500 | 5.285021e-8 |
| 1000 | 1.057004e-7 |
The megameter is a unit of length equal to 10⁶ meters (1,000 kilometers or one million meters).
1 Mm = 10⁶ m = 1,000 km = 1,000,000 m.
To convert Mm to km: multiply by 1,000. To convert Mm to miles: multiply by 621.371.
Describing planetary diameters and distances within the solar system in a compact metric form.
Earth's diameter ≈ 12.7 Mm. The circumference of Earth ≈ 40 Mm — this is by design, as the meter was originally defined from it.
Uppercase matters: 'Mm' = megameter (10⁶ m), 'mm' = millimeter (10⁻³ m) — a factor of 10⁹ difference!
Remember the SI prefix pattern: kilo (10³), mega (10⁶), giga (10⁹). Each step is 1,000× larger.
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.



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