Length · Unit Converter

Convert Earth's Equatorial Radius to Millimeter

Convert earth's equatorial radii to millimeters instantly. 1 earth's equatorial radius = 6.378137e+9 millimeter — use the live calculator, the exact formula, a conversion table and worked examples. Also check the Millimeter to Earth's Equatorial Radius converter for the reverse conversion.

Written by Sunith Babu L, Ph.D., Lead Engineer Reviewed by Girish V Kulkarni Ph.D.
Length category 2 min read Published Last reviewed Updated

Units explained

Astronomical

Earth's Equatorial Radius

What is a 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.

Origin of the earth's equatorial radius

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.

Where it is used

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.

When and where it was developed

WGS84 reference ellipsoid adopted in 1984 by the US Department of Defense; subsequently adopted globally for GPS and civilian geodesy.

Metric / SI

Millimeter

What is a 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.

Origin of the millimeter

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.

Where it is used

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.

When and where it was developed

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 to Millimeter conversion formula

The relationship between earth's equatorial radii and millimeters:

1 R⊕,eq = 6.378137e+9 mm
1 mm = 1.567856e-10 R⊕,eq

To convert earth's equatorial radii to millimeters, multiply the value in earth's equatorial radii by 6.378137e+9. To reverse, multiply millimeters by 1.567856e-10.

How to use this converter

Type a value into the calculator. The result in millimeters updates as you type. Tap a quick value, copy the result with one click, or use the swap arrow to jump straight to the Millimeter to Earth's Equatorial Radius converter for the reverse direction.

Step-by-step: convert earth's equatorial radii to millimeters

  1. Write down the value in earth's equatorial radii (R⊕,eq).
  2. Multiply that value by the factor 6.378137e+9.
  3. The product is the equivalent value in millimeters (mm).
  4. To reverse, multiply the millimeter value by 1.567856e-10.

Worked examples

Example 1 — Convert 1 R⊕,eq to mm:
1 × 6.378137e+9 = 6.378137e+9 mm

Example 2 — Convert 100 R⊕,eq to mm:
100 × 6.378137e+9 = 6.378137e+11 mm

Earth's Equatorial Radius to Millimeter conversion table

Standard reference values for converting earth's equatorial radii to millimeters:

Earth's Equatorial Radius [R⊕,eq]Millimeter [mm]
0.016.378137e+7
0.16.378137e+8
16.378137e+9
21.275627e+10
31.913441e+10
42.551255e+10
53.189068e+10
106.378137e+10
201.275627e+11
301.913441e+11
402.551255e+11
503.189068e+11
1006.378137e+11
5003.189068e+12
10006.378137e+12

Frequently asked questions

How many millimeters is 1 earth's equatorial radius?
1 earth's equatorial radius equals 6.378137e+9 millimeter.
How do I convert earth's equatorial radii to millimeters?
Multiply the value in earth's equatorial radii by 6.378137e+9 to get millimeters.
How do I convert millimeters back to earth's equatorial radii?
Multiply the value in millimeters by 1.567856e-10, or use the Millimeter to Earth's Equatorial Radius converter.
How many millimeters is 100 earth's equatorial radii?
100 earth's equatorial radii equals 6.378137e+11 millimeters, because 100 × 6.378137e+9 = 6.378137e+11.

Convert Earth's Equatorial Radius to other length units

Show all Earth's Equatorial Radius conversions

Sources & references

Conversion factor (1 R⊕,eq = 6.378137e+9 mm) verified against the following authoritative sources:

Results are provided for general reference. Verify critical measurements against an authoritative standard.