Convert Astronomical Unit to Earth's Equatorial Radius
Convert astronomical units to earth's equatorial radii instantly. 1 astronomical unit = 23454.7910620296 earth's equatorial radius — use the live calculator, the exact formula, a conversion table and worked examples. Also check the Earth's Equatorial 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 Equatorial Radius
Earth's equatorial radius is the distance from the planet's center to its surface at the equator, defined as exactly 6,378,137 meters by the WGS84 geodetic reference system.
The WGS84 (World Geodetic System 1984) defines Earth's reference ellipsoid for use in GPS and global cartography. The 6,378,137 m equatorial value was determined through satellite and ground geodetic measurements consolidated in 1984.
WGS84's equatorial radius is the standard reference for GPS, satellite imagery, geographic information systems, and aviation navigation. It defines the 'a' parameter of Earth's reference ellipsoid in coordinate transformations.
WGS84 reference ellipsoid adopted in 1984 by the US Department of Defense; subsequently adopted globally for GPS and civilian geodesy.
Astronomical Unit to Earth's Equatorial Radius conversion formula
The relationship between astronomical units and earth's equatorial radii:
To convert astronomical units to earth's equatorial radii, multiply the value in astronomical units by 23454.7910620296. To reverse, multiply earth's equatorial radii by 4.263521e-5.
How to use this converter
Type a value into the calculator. The result in earth's equatorial 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 Equatorial Radius to Astronomical Unit converter for the reverse direction.
Step-by-step: convert astronomical units to earth's equatorial radii
- Write down the value in astronomical units (AU).
- Multiply that value by the factor 23454.7910620296.
- The product is the equivalent value in earth's equatorial radii (R⊕,eq).
- To reverse, multiply the earth's equatorial radius value by 4.263521e-5.
Worked examples
Example 1 — Convert 1 AU to R⊕,eq:
1 × 23454.7910620296 = 23454.7910620296 R⊕,eq
Example 2 — Convert 100 AU to R⊕,eq:
100 × 23454.7910620296 = 2345479.1062029554 R⊕,eq
Astronomical Unit to Earth's Equatorial Radius conversion table
Standard reference values for converting astronomical units to earth's equatorial radii:
| Astronomical Unit [AU] | Earth's Equatorial Radius [R⊕,eq] |
|---|---|
| 0.01 | 234.5479106203 |
| 0.1 | 2345.479106203 |
| 1 | 23454.7910620296 |
| 2 | 46909.5821240591 |
| 3 | 70364.3731860887 |
| 4 | 93819.1642481182 |
| 5 | 117273.9553101478 |
| 10 | 234547.9106202956 |
| 20 | 469095.8212405911 |
| 30 | 703643.7318608867 |
| 40 | 938191.6424811822 |
| 50 | 1172739.5531014777 |
| 100 | 2345479.1062029554 |
| 500 | 1.17274e+7 |
| 1000 | 2.345479e+7 |
Frequently asked questions
How many earth's equatorial radii is 1 astronomical unit?
How do I convert astronomical units to earth's equatorial radii?
How do I convert earth's equatorial radii back to astronomical units?
How many earth's equatorial radii is 100 astronomical units?
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Sources & references
Conversion factor (1 AU = 23454.7910620296 R⊕,eq) 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.