Important fundamental constants are available in SI units (feature "const SI")
In this menu you can select from a list of important fundamental constants, given in international SI units. The values for the fundamental physical constants are the ones currently recommended e.g. by the German national metrological institute (Physikalisch Technische Bundesanstalt PTB). The following constants are given in SI units:
- h: Planck's constant
- hbar: h/2/Pi
- c0: vacuum speed of light
- kB: Boltzmann constant
- NA: Avogadro constant
- R: molar gas constant
- e: electron charge
- me: electron mass
- mp: proton mass
- mn: neutron mass
- mp/me: ratio of proton and electron mass
- u: atomic unit
- epsilon0: electrical field constant
- my0: magnetic field constant
- G: gravitational constant
