Fermi coupling constant also known as Fermi Constant deals with the capacity of Fermi's interaction. It is denoted as GF. It is also termed as Fermi's constant. The constant is related to the Higgs vacuum expectation value in the standard model. The value of Fermi's constant is 1.16637 x 10 ^-5 GeV-2. It is equivalent to 1.16637 x e^4 eV-2.