Convert femtometer to perch 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.

Perch

A perch is an old unit of length that is synonymous with the rod or pole, commonly used in land measurement and surveying. It measures 16.5 feet, 5.5 yards, or approximately 5.0292 meters.

The perch was widely used in England and later in the United States for measuring plots of land, especially before the widespread adoption of the metric system. It was also used to describe area when squared (square perch).

Key points:

• 
  

  1 perch = 16.5 feet

  
  
• 
  

  1 perch = 5.5 yards

  
  
• 
  

  1 perch ≈ 5.0292 meters

  
  
• 
  

  4 perches = 1 chain

  
  
• 
  

  40 perches = 1 furlong

  
  

While largely obsolete today, the term perch still appears in historical land deeds, legal documents, and some traditional surveying contexts.