Convert Millimeter to Earth's Equatorial Radius
Convert millimeters to earth's equatorial radii instantly. 1 millimeter = 1.567856e-10 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 Millimeter converter for the reverse conversion.
Units explained
Millimeter
A millimeter is a metric unit of length equal to one thousandth of a meter (1/1000 m). It is the standard small-scale unit in the SI system and is widely used wherever sub-centimeter precision matters.
The millimeter was defined alongside the meter when France adopted the metric system in 1795, using the standard SI prefix milli- (from Latin mille, "thousand") to denote one-thousandth.
Millimeters are used in engineering drawings, machining, manufacturing, paper sizes, rainfall measurement, and any context where dimensions below one centimeter need to be specified clearly. Most rulers worldwide are marked in millimeters.
Adopted in 1795 in France as part of the original metric system; standardized internationally by the Metre Convention in 1875 and confirmed in the SI in 1960.
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.
Millimeter to Earth's Equatorial Radius conversion formula
The relationship between millimeters and earth's equatorial radii:
To convert millimeters to earth's equatorial radii, multiply the value in millimeters by 1.567856e-10. To reverse, multiply earth's equatorial radii by 6.378137e+9.
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 Millimeter converter for the reverse direction.
Step-by-step: convert millimeters to earth's equatorial radii
- Write down the value in millimeters (mm).
- Multiply that value by the factor 1.567856e-10.
- The product is the equivalent value in earth's equatorial radii (R⊕,eq).
- To reverse, multiply the earth's equatorial radius value by 6.378137e+9.
Worked examples
Example 1 — Convert 1 mm to R⊕,eq:
1 × 1.567856e-10 = 1.567856e-10 R⊕,eq
Example 2 — Convert 100 mm to R⊕,eq:
100 × 1.567856e-10 = 1.567856e-8 R⊕,eq
Real-world example — Postcard and small-object dimensions
A postcard is about 5 millimeters wide. Converting to earth's equatorial radii is essential for international postal addressing forms that ask for dimensions in different units across countries.
5 mm × 1.567856e-10 = 7.83928e-10 R⊕,eq
Real-world example — Ruler-scale measurements
A 30-millimeter school ruler converts cleanly to earth's equatorial radii — useful when buying a desk accessory from a retailer whose product specs use a different unit.
30 mm × 1.567856e-10 = 4.703568e-9 R⊕,eq
Real-world example — Hardware-scale dimensions
A 10-millimeter fastener or component is about as long as a thumbnail. Mechanics and DIY enthusiasts convert between millimeters and earth's equatorial radii daily when mixing metric and imperial tools.
10 mm × 1.567856e-10 = 1.567856e-9 R⊕,eq
Millimeter to Earth's Equatorial Radius conversion table
Standard reference values for converting millimeters to earth's equatorial radii:
| Millimeter [mm] | Earth's Equatorial Radius [R⊕,eq] |
|---|---|
| 0.01 | 1.567856e-12 |
| 0.1 | 1.567856e-11 |
| 1 | 1.567856e-10 |
| 2 | 3.135712e-10 |
| 3 | 4.703568e-10 |
| 4 | 6.271424e-10 |
| 5 | 7.83928e-10 |
| 10 | 1.567856e-9 |
| 20 | 3.135712e-9 |
| 30 | 4.703568e-9 |
| 40 | 6.271424e-9 |
| 50 | 7.83928e-9 |
| 100 | 1.567856e-8 |
| 500 | 7.83928e-8 |
| 1000 | 1.567856e-7 |
Frequently asked questions
How many earth's equatorial radii is 1 millimeter?
How do I convert millimeters to earth's equatorial radii?
How do I convert earth's equatorial radii back to millimeters?
How many earth's equatorial radii is 100 millimeters?
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Metric / SI (17 units)
Imperial / US Customary (27 units)
Nautical (1 units)
Astronomical (9 units)
Atomic / Physics (6 units)
Typographic (3 units)
Sources & references
Conversion factor (1 mm = 1.567856e-10 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.