Form factor

The term form factor may refer to:

• In physical sciences:
  • In scattering theory:
    • Form factor (quantum field theory), a semi-empirical formula used in effective quantum field theories;
    • Electric form factor, the Fourier transform of electric charge distribution in space;
    • Magnetic form factor, the Fourier transform of an electric current distribution in space;
    • Atomic form factor, or atomic scattering factor, a measure of the amplitude of a wave scattered from an isolated atom.
  • Form factor (radiative transfer) or emissivity, the proportion of energy transmitted by that object which can be transferred to another object;
  • Form factor (electronics), characterizing the functional form of oscillating signals.

• In evaluating shapes of objects
  • In forest inventory, a factor in timber metrics referring to the tree shape.

• The design and geometry of a product, especially in industrial and engineering design, including:
  • Computer form factor, the industry-standard physical dimensions of the major components of computers
  • Hard disk drive form factor, the physical dimensions of a computer hard drive
  • Hard disk enclosure form factor, the physical dimensions of a computer hard drive enclosure
  • Mobile phone form factor, the fundamental design of a mobile phone
  • Small form factor, a system smaller than a traditional mini-tower, such as a book-sized PC or a miniature Home Theater PC (HTPC)
  • Pizza box form factor, a style of case, usually wide and flat, for computers or network switches