Convert Light Year to Earth's Equatorial Radius
Convert light years to earth's equatorial radii instantly. 1 light year = 1.483306e+9 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 Light Year converter for the reverse conversion.
Units explained
Light Year
A light year is the distance light travels in one Julian year in vacuum — exactly 9,460,730,472,580,800 meters (about 9.46×10¹⁵ m). It is the most common unit for expressing inter-stellar distances in non-technical astronomy.
Defined as the speed of light (299,792,458 m/s, exact) multiplied by one Julian year (365.25 days × 86400 seconds/day). Both factors are exact, making the light year exact by definition.
Light years are used in popular astronomy, science journalism, and stellar distance descriptions. The nearest star (Proxima Centauri) is 4.24 ly away; the Milky Way is about 100,000 ly across.
Concept of distance-as-time used since the 19th century; the modern exact definition follows from the 1983 SI definition of the meter via the speed of light.
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.
Light Year to Earth's Equatorial Radius conversion formula
The relationship between light years and earth's equatorial radii:
To convert light years to earth's equatorial radii, multiply the value in light years by 1.483306e+9. To reverse, multiply earth's equatorial radii by 6.741696e-10.
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 Light Year converter for the reverse direction.
Step-by-step: convert light years to earth's equatorial radii
- Write down the value in light years (ly).
- Multiply that value by the factor 1.483306e+9.
- The product is the equivalent value in earth's equatorial radii (R⊕,eq).
- To reverse, multiply the earth's equatorial radius value by 6.741696e-10.
Worked examples
Example 1 — Convert 1 ly to R⊕,eq:
1 × 1.483306e+9 = 1.483306e+9 R⊕,eq
Example 2 — Convert 100 ly to R⊕,eq:
100 × 1.483306e+9 = 1.483306e+11 R⊕,eq
Light Year to Earth's Equatorial Radius conversion table
Standard reference values for converting light years to earth's equatorial radii:
| Light Year [ly] | Earth's Equatorial Radius [R⊕,eq] |
|---|---|
| 0.01 | 1.483306e+7 |
| 0.1 | 1.483306e+8 |
| 1 | 1.483306e+9 |
| 2 | 2.966612e+9 |
| 3 | 4.449919e+9 |
| 4 | 5.933225e+9 |
| 5 | 7.416531e+9 |
| 10 | 1.483306e+10 |
| 20 | 2.966612e+10 |
| 30 | 4.449919e+10 |
| 40 | 5.933225e+10 |
| 50 | 7.416531e+10 |
| 100 | 1.483306e+11 |
| 500 | 7.416531e+11 |
| 1000 | 1.483306e+12 |
Frequently asked questions
How many earth's equatorial radii is 1 light year?
How do I convert light years to earth's equatorial radii?
How do I convert earth's equatorial radii back to light years?
How many earth's equatorial radii is 100 light years?
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Imperial / US Customary (4 units)
Astronomical (8 units)
Sources & references
Conversion factor (1 ly = 1.483306e+9 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.