Convert Earth equatorial radius to foot (US survey) Online | Free Length Converter

Earth Equatorial Radius

The Earth's equatorial radius is the distance from the center of the Earth to the equator. It represents the Earth's radius measured along the equatorial plane.

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  Its value is approximately 6,378.1 kilometers (about 3,963.2 miles).

  
  
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  The Earth is not a perfect sphere but an oblate spheroid, so the equatorial radius is slightly larger than the polar radius.

  
  
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  This radius is important for geodesy, satellite orbits, and mapping.

  
  

Key facts:

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  Equatorial radius ≈ 6,378.1 km

  
  
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  Larger than polar radius due to Earth's flattening at the poles

  
  
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  Used in Earth sciences, navigation, and space missions

  
  

Understanding the Earth's equatorial radius helps in accurate modeling of the planet’s shape and gravitational field.

Foot (US Survey)

The US survey foot is a unit of length used historically in the United States for land surveying and mapping. It is defined as exactly 1200/3937 meters, which is approximately 0.3048006096 meters. This makes it very slightly longer than the international foot, which is exactly 0.3048 meters.

The US survey foot was established to maintain consistency with earlier land surveys and legal descriptions in the U.S. It was used extensively in the Public Land Survey System and other cadastral surveys.

Key points:

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  1 US survey foot = 1200/3937 meters ≈ 0.3048006096 meters

  
  
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  Slightly longer than the international foot by about 0.0006 millimeters

  
  
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  Used primarily in land surveying and legal documents

  
  
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  As of recent years, the US has been phasing out the US survey foot in favor of the international foot for standardization.

  
  

Though nearly identical to the international foot, the US survey foot remains important for understanding older land records and measurements.