Convert Astronomical Unit to Earth's Polar Radius
Convert astronomical units to earth's polar radii instantly. 1 astronomical unit = 23533.6962492795 earth's polar radius — use the live calculator, the exact formula, a conversion table and worked examples. Also check the Earth's Polar Radius to Astronomical Unit converter for the reverse conversion.
Units explained
Astronomical Unit
The astronomical unit (AU) is a unit of length equal to exactly 149,597,870,700 meters, approximately the average distance from Earth to the Sun. It is the fundamental unit for distance within the solar system.
The AU was originally defined as the semi-major axis of Earth's orbit. In 2012, IAU Resolution B2 redefined the AU as exactly 149,597,870,700 meters, severing its dependence on the actual fluctuating Earth–Sun distance.
AUs are used to express distances within the solar system (Mars: 1.5 AU, Pluto: ~40 AU at perihelion), exoplanet orbital radii, and other planetary-scale distances. Standard in planetary science and astronomy.
Original definition tied to Earth's orbit (Newton, 17th century); fixed at exactly 149,597,870,700 m by IAU Resolution B2 in 2012.
Earth's Polar Radius
Earth's polar radius is the distance from the planet's center to either pole, approximately 6,356,752 meters under the WGS84 geodetic reference system. The polar radius is about 21 km shorter than the equatorial radius due to Earth's oblate spheroid shape.
Derived from WGS84's flattening parameter (f ≈ 1/298.257); the difference from the equatorial radius is the geometric signature of Earth's rotational oblateness.
Earth's polar radius is used in geodesy, satellite-orbit calculations, and global cartography. Together with the equatorial radius it defines Earth's reference ellipsoid in WGS84.
Derived from the WGS84 reference ellipsoid adopted in 1984; the value is computed from the equatorial radius minus the oblateness.
Astronomical Unit to Earth's Polar Radius conversion formula
The relationship between astronomical units and earth's polar radii:
To convert astronomical units to earth's polar radii, multiply the value in astronomical units by 23533.6962492795. To reverse, multiply earth's polar radii by 4.249226e-5.
How to use this converter
Type a value into the calculator. The result in earth's polar radii updates as you type. Tap a quick value, copy the result with one click, or use the swap arrow to jump straight to the Earth's Polar Radius to Astronomical Unit converter for the reverse direction.
Step-by-step: convert astronomical units to earth's polar radii
- Write down the value in astronomical units (AU).
- Multiply that value by the factor 23533.6962492795.
- The product is the equivalent value in earth's polar radii (R⊕,p).
- To reverse, multiply the earth's polar radius value by 4.249226e-5.
Worked examples
Example 1 — Convert 1 AU to R⊕,p:
1 × 23533.6962492795 = 23533.6962492795 R⊕,p
Example 2 — Convert 100 AU to R⊕,p:
100 × 23533.6962492795 = 2353369.6249279506 R⊕,p
Astronomical Unit to Earth's Polar Radius conversion table
Standard reference values for converting astronomical units to earth's polar radii:
| Astronomical Unit [AU] | Earth's Polar Radius [R⊕,p] |
|---|---|
| 0.01 | 235.3369624928 |
| 0.1 | 2353.369624928 |
| 1 | 23533.6962492795 |
| 2 | 47067.392498559 |
| 3 | 70601.0887478385 |
| 4 | 94134.784997118 |
| 5 | 117668.4812463975 |
| 10 | 235336.9624927951 |
| 20 | 470673.9249855902 |
| 30 | 706010.8874783852 |
| 40 | 941347.8499711803 |
| 50 | 1176684.8124639753 |
| 100 | 2353369.6249279506 |
| 500 | 1.176685e+7 |
| 1000 | 2.35337e+7 |
Frequently asked questions
How many earth's polar radii is 1 astronomical unit?
How do I convert astronomical units to earth's polar radii?
How do I convert earth's polar radii back to astronomical units?
How many earth's polar radii is 100 astronomical units?
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Sources & references
Conversion factor (1 AU = 23533.6962492795 R⊕,p) verified against the following authoritative sources:
- BIPM — The International System of Units (SI Brochure 9th ed.)
Official BIPM publication defining the seven SI base units (including the meter) and the rules for their use. The global authority on units of measurement.
- NIST — Guide to the SI
US National Institute of Standards and Technology reference covering the SI base and derived units with definitions and usage rules for US technical practice.
- NIST Special Publication 811 — Guide for the Use of the International System of Units
Detailed NIST guide covering exact conversion factors between SI and US customary units along with formatting and rounding conventions.
- NIST — Refinement of values for the yard and pound (Federal Register 1959)
The treaty (signed by US
- International Astronomical Union — System of Astronomical Constants
The IAU defines astronomical units including the AU (149597870700 m exactly) light-year and parsec used in astronomy and astrophysics.