Instant · Precise · Universal
32 units available
6 categories total
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)) = 6.378137e+18 Picometer (pm).
| Earth's Equatorial Radius (R⊕ (eq)) | Picometer (pm) |
|---|---|
| 0.1 | 6.378137e+17 |
| 0.5 | 3.189069e+18 |
| 1 | 6.378137e+18 |
| 2 | 1.275627e+19 |
| 5 | 3.189069e+19 |
| 10 | 6.378137e+19 |
| 25 | 1.594534e+20 |
| 50 | 3.189068e+20 |
| 100 | 6.378137e+20 |
| 500 | 3.189068e+21 |
| 1000 | 6.378137e+21 |
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.
The picometer is a unit of length equal to 10⁻¹² meters, or one trillionth of a meter.
1 pm = 10⁻¹² m = 0.01 Å = 1,000 fm. One nanometer equals 1,000 picometers.
To convert pm to meters: multiply by 10⁻¹². To convert pm to angstroms: divide by 100.
Expressing covalent bond lengths (e.g., C–C bond ≈ 154 pm), atomic radii, and crystal lattice spacings.
The hydrogen atom has a radius of about 53 pm (the Bohr radius), while a carbon-carbon single bond is about 154 pm long.
Mixing up picometers and nanometers — remember 1 nm = 1,000 pm. Some sources still use the deprecated angstrom.
Think of pm as the natural unit for atoms: most atomic radii fall between 30 pm and 300 pm.



© 2026 UntangleTools. All Rights Reserved.