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) = 0.1567855943 Earth's Equatorial Radius (R⊕ (eq)).
| Megameter (Mm) | Earth's Equatorial Radius (R⊕ (eq)) |
|---|---|
| 0.1 | 0.01567855943 |
| 0.5 | 0.07839279714 |
| 1 | 0.1567855943 |
| 2 | 0.3135711886 |
| 5 | 0.7839279714 |
| 10 | 1.567855943 |
| 25 | 3.919639857 |
| 50 | 7.839279714 |
| 100 | 15.67855943 |
| 500 | 78.39279714 |
| 1000 | 156.7855943 |
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 Earth's equatorial radius is the distance from Earth's center to the equator, approximately 6,378.137 km.
R⊕(eq) = 6,378,137 m = 6,378.137 km. Earth's oblateness = (R_eq − R_pol)/R_eq ≈ 1/298.257.
To convert Earth radii to meters: multiply by 6,378,137.
GPS calculations, satellite orbit determination, map projections, and geophysical modeling.
Earth is not a perfect sphere — the equatorial radius is about 21 km (0.3%) larger than the polar radius due to rotational flattening.
Using the equatorial radius as if Earth were a sphere — for precision, you must account for the oblate spheroid shape.
Earth's equatorial radius (6,378 km) vs. polar radius (6,357 km) shows the planet bulges at the equator due to spinning.



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