Convert femtometer to foot (US survey) Online | Free Length Converter

Femtometer

A femtometer (fm) is a unit of length in the metric system, equal to one-quadrillionth of a meter (1 fm = 10⁻¹⁵ meters). It is also known as a fermi, named after the physicist Enrico Fermi. Femtometers are used to measure extremely small distances at the subatomic level, such as the size of protons, neutrons, and atomic nuclei. For example, the radius of a proton is about 0.84 femtometers. This unit is commonly used in nuclear physics and particle physics, but it's far too small for everyday measurements.

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.

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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.