Length · Unit Converter

Convert Earth's Polar Radius to Mile

Convert earth's polar radii to miles instantly. 1 earth's polar radius = 3949.9025689971 mile — use the live calculator, the exact formula, a conversion table and worked examples. Also check the Mile to Earth's Polar 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 Polar Radius

What is a 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.

Origin of the earth's polar radius

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.

Where it is used

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.

When and where it was developed

Derived from the WGS84 reference ellipsoid adopted in 1984; the value is computed from the equatorial radius minus the oblateness.

Imperial / US Customary

Mile

What is a mile?

A mile (statute mile) is an Imperial and US customary unit of length equal to 5,280 feet or exactly 1,609.344 meters. It is the standard unit for road distances in the United States and the United Kingdom.

Origin of the mile

The mile derives from the Roman mille passus ("thousand paces" — about 1,480 meters). The English statute mile was fixed at 5,280 feet by the Weights and Measures Act of 1593, and exactly defined as 1,609.344 m by the 1959 International Yard and Pound Agreement.

Where it is used

Miles are used in the US and UK for road signs, speed limits (mph), athletic events (one-mile run), and geographic distances. Aviation also uses statute miles for some visibility measurements.

When and where it was developed

Roman origin (mille passus); English statute mile fixed at 5,280 feet in 1593; standardized to 1,609.344 m exactly by the 1959 International Yard and Pound Agreement.

Earth's Polar Radius to Mile conversion formula

The relationship between earth's polar radii and miles:

1 R⊕,p = 3949.9025689971 mi
1 mi = 0.0002531708 R⊕,p

To convert earth's polar radii to miles, multiply the value in earth's polar radii by 3949.9025689971. To reverse, multiply miles by 0.0002531708.

How to use this converter

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

Step-by-step: convert earth's polar radii to miles

  1. Write down the value in earth's polar radii (R⊕,p).
  2. Multiply that value by the factor 3949.9025689971.
  3. The product is the equivalent value in miles (mi).
  4. To reverse, multiply the mile value by 0.0002531708.

Worked examples

Example 1 — Convert 1 R⊕,p to mi:
1 × 3949.9025689971 = 3949.9025689971 mi

Example 2 — Convert 100 R⊕,p to mi:
100 × 3949.9025689971 = 394990.2568997057 mi

Earth's Polar Radius to Mile conversion table

Standard reference values for converting earth's polar radii to miles:

Earth's Polar Radius [R⊕,p]Mile [mi]
0.0139.49902569
0.1394.9902568997
13949.9025689971
27899.8051379941
311849.7077069912
415799.6102759882
519749.5128449853
1039499.0256899706
2078998.0513799411
30118497.0770699117
40157996.1027598823
50197495.1284498529
100394990.2568997057
5001974951.2844985286
10003949902.5689970572

Frequently asked questions

How many miles is 1 earth's polar radius?
1 earth's polar radius equals 3949.9025689971 mile.
How do I convert earth's polar radii to miles?
Multiply the value in earth's polar radii by 3949.9025689971 to get miles.
How do I convert miles back to earth's polar radii?
Multiply the value in miles by 0.0002531708, or use the Mile to Earth's Polar Radius converter.
How many miles is 100 earth's polar radii?
100 earth's polar radii equals 394990.2568997057 miles, because 100 × 3949.9025689971 = 394990.2568997057.

Convert Earth's Polar Radius to other length units

Show all Earth's Polar Radius conversions

Sources & references

Conversion factor (1 R⊕,p = 3949.9025689971 mi) verified against the following authoritative sources:

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