Convert Earth polar radius to link (US survey) Online | Free Length Converter

Earth Polar Radius

The Earth's polar radius is the distance from the center of the Earth to the North or South Pole. It measures the Earth’s radius along its rotational axis.

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  Its value is approximately 6,356.8 kilometers (about 3,949.9 miles).

  
  
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  The Earth is an oblate spheroid, so the polar radius is slightly shorter than the equatorial radius due to the planet's flattening at the poles.

  
  
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  This measurement is crucial for geodesy, understanding Earth’s shape, and satellite navigation.

  
  

Key facts:

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  Polar radius ≈ 6,356.8 km

  
  
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  Smaller than equatorial radius by about 21.3 km

  
  
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  Important for precise Earth modeling and mapping

  
  

The difference between the polar and equatorial radius reflects the Earth’s rotation and its effect on the planet’s shape.

Link (US Survey)

The US survey link is a unit of length used in the United States for land surveying, defined as exactly 7.92 US survey inches. Since one US survey inch is slightly longer than the international inch (due to the US survey foot), the US survey link is approximately 0.201168 meters.

It is part of the US survey system, derived from Gunter’s chain, which is divided into 100 links per chain (66 US survey feet). Links are used to measure small distances in surveying and land measurement.

Key facts:

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  1 US survey link = 7.92 US survey inches

  
  
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  1 US survey link ≈ 0.201168 meters

  
  
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  100 links = 1 US survey chain (66 US survey feet)

  
  
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  25 links = 1 US survey rod (16.5 US survey feet)

  
  

Though the US survey units are being phased out, the US survey link still appears in historical land records and legal surveying documents.