Earth's Equatorial Radius to Earth's Polar Radius Converter
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Instant · Precise · Universal
32 units available
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How to Convert Earth's Equatorial Radius to Earth's Polar Radius
To convert Earth radii to meters: multiply by 6,378,137.
R⊕(eq) = 6,378,137 m = 6,378.137 km. Earth's oblateness = (R_eq − R_pol)/R_eq ≈ 1/298.257.
For example, 1 Earth's Equatorial Radius (R⊕ (eq)) = 1.003364092 Earth's Polar Radius (R⊕ (polar)).
Earth's Equatorial Radius to Earth's Polar Radius — Common Values
| Earth's Equatorial Radius (R⊕ (eq)) | Earth's Polar Radius (R⊕ (polar)) |
|---|---|
| 0.1 | 0.1003364092 |
| 0.5 | 0.501682046 |
| 1 | 1.003364092 |
| 2 | 2.006728184 |
| 5 | 5.01682046 |
| 10 | 10.03364092 |
| 25 | 25.0841023 |
| 50 | 50.1682046 |
| 100 | 100.3364092 |
| 500 | 501.682046 |
| 1000 | 1003.364092 |
About Earth's Equatorial Radius (R⊕ (eq))
Definition
The Earth's equatorial radius is the distance from Earth's center to the equator, approximately 6,378.137 km.
Mathematical Relationship
R⊕(eq) = 6,378,137 m = 6,378.137 km. Earth's oblateness = (R_eq − R_pol)/R_eq ≈ 1/298.257.
Conversion Formula
To convert Earth radii to meters: multiply by 6,378,137.
Practical Applications
GPS calculations, satellite orbit determination, map projections, and geophysical modeling.
Interesting Facts
Earth is not a perfect sphere — the equatorial radius is about 21 km (0.3%) larger than the polar radius due to rotational flattening.
Common Mistakes
Using the equatorial radius as if Earth were a sphere — for precision, you must account for the oblate spheroid shape.
Educational Tips
Earth's equatorial radius (6,378 km) vs. polar radius (6,357 km) shows the planet bulges at the equator due to spinning.
About Earth's Polar Radius (R⊕ (polar))
Definition
The Earth's polar radius is the distance from Earth's center to either pole, approximately 6,356.752 km.
Mathematical Relationship
R⊕(polar) = 6,356,752.3 m. It is about 21.385 km shorter than the equatorial radius.
Conversion Formula
To convert Earth polar radii to meters: multiply by 6,356,752.3.
Practical Applications
Geodetic calculations, gravity modeling, and precise cartography near the poles.
Interesting Facts
At the poles, you are about 21 km closer to Earth's center than at the equator — you weigh very slightly more!
Common Mistakes
Approximating Earth as a perfect sphere — the difference between equatorial and polar radii matters for precision applications.
Educational Tips
Earth's shape (oblate spheroid) is like a slightly squished ball — wider at the equator, flatter at the poles.