# Math & Scientific Constants Reference Browse built-in mathematical and scientific constants, including pi, e, the speed of light, Planck constants, particle masses, and exact SI values. ## Constants Complete overview of constants available on calcul.io | [atomicMass](https://calcul.io/constants/atomicMass/index.md) | Atomic mass constant | | --- | --- | | [avogadro](https://calcul.io/constants/avogadro/index.md) | Avogadro's number | | [bohrMagneton](https://calcul.io/constants/bohrMagneton/index.md) | Borh magneton | | [bohrRadius](https://calcul.io/constants/bohrRadius/index.md) | Borh radius | | [boltzmann](https://calcul.io/constants/boltzmann/index.md) | Boltzmann constant | | [classicalElectronRadius](https://calcul.io/constants/classicalElectronRadius/index.md) | Classical electron radius | | [conductanceQuantum](https://calcul.io/constants/conductanceQuantum/index.md) | Conductance quantum | | [coulomb](https://calcul.io/constants/coulomb/index.md) | Coulomb's constant | | [deuteronMass](https://calcul.io/constants/deuteronMass/index.md) | Deuteron Mass | | [e](https://calcul.io/constants/e/index.md) | | | [efimovFactor](https://calcul.io/constants/efimovFactor/index.md) | Efimov factor | | [electricConstant](https://calcul.io/constants/electricConstant/index.md) | Electric constant (vacuum permeability) | | [electronMass](https://calcul.io/constants/electronMass/index.md) | Electron mass | | [elementaryCharge](https://calcul.io/constants/elementaryCharge/index.md) | Elementary charge | | [false](https://calcul.io/constants/false/index.md) | | | [faraday](https://calcul.io/constants/faraday/index.md) | Faraday constant | | [fermiCoupling](https://calcul.io/constants/fermiCoupling/index.md) | Fermi coupling constant | | [fineStructure](https://calcul.io/constants/fineStructure/index.md) | Fine-structure constant | | [firstRadiation](https://calcul.io/constants/firstRadiation/index.md) | First radiation constant | | [gasConstant](https://calcul.io/constants/gasConstant/index.md) | Gas constant | | [gravitationConstant](https://calcul.io/constants/gravitationConstant/index.md) | Newtonian constant of gravitation | | [gravity](https://calcul.io/constants/gravity/index.md) | Standard acceleration of gravity (standard acceleration of free-fall on Earth) | | [hartreeEnergy](https://calcul.io/constants/hartreeEnergy/index.md) | Hartree energy | | [i](https://calcul.io/constants/i/index.md) | | | [Infinity](https://calcul.io/constants/Infinity/index.md) | | | [inverseConductanceQuantum](https://calcul.io/constants/inverseConductanceQuantum/index.md) | Inverse conductance quantum | | [klitzing](https://calcul.io/constants/klitzing/index.md) | Von Klitzing constant | | [LN10](https://calcul.io/constants/LN10/index.md) | | | [LN2](https://calcul.io/constants/LN2/index.md) | | | [LOG10E](https://calcul.io/constants/LOG10E/index.md) | | | [LOG2E](https://calcul.io/constants/LOG2E/index.md) | | | [loschmidt](https://calcul.io/constants/loschmidt/index.md) | Loschmidt constant at T=273.15 K and p=101.325 kPa | | [magneticConstant](https://calcul.io/constants/magneticConstant/index.md) | Magnetic constant (vacuum permeability) | | [magneticFluxQuantum](https://calcul.io/constants/magneticFluxQuantum/index.md) | Magnetic flux quantum | | [molarMass](https://calcul.io/constants/molarMass/index.md) | Molar mass constant | | [molarMassC12](https://calcul.io/constants/molarMassC12/index.md) | Molar mass constant of carbon-12 | | [molarPlanckConstant](https://calcul.io/constants/molarPlanckConstant/index.md) | Molar Planck constant | | [molarVolume](https://calcul.io/constants/molarVolume/index.md) | Molar volume of an ideal gas at T=273.15 K and p=101.325 kPa | | [NaN](https://calcul.io/constants/NaN/index.md) | | | [neutronMass](https://calcul.io/constants/neutronMass/index.md) | Neutron mass | | [nuclearMagneton](https://calcul.io/constants/nuclearMagneton/index.md) | Nuclear magneton | | [null](https://calcul.io/constants/null/index.md) | | | [phi](https://calcul.io/constants/phi/index.md) | | | [pi](https://calcul.io/constants/pi/index.md) | | | [planckCharge](https://calcul.io/constants/planckCharge/index.md) | Planck charge | | [planckConstant](https://calcul.io/constants/planckConstant/index.md) | Planck constant | | [planckLength](https://calcul.io/constants/planckLength/index.md) | Planck length | | [planckMass](https://calcul.io/constants/planckMass/index.md) | Planck mass | | [planckTemperature](https://calcul.io/constants/planckTemperature/index.md) | Planck temperature | | [planckTime](https://calcul.io/constants/planckTime/index.md) | Planck time | | [protonMass](https://calcul.io/constants/protonMass/index.md) | Proton mass | | [quantumOfCirculation](https://calcul.io/constants/quantumOfCirculation/index.md) | Quantum of circulation | | [reducedPlanckConstant](https://calcul.io/constants/reducedPlanckConstant/index.md) | Reduced Planck constant | | [rydberg](https://calcul.io/constants/rydberg/index.md) | Rydberg constant | | [sackurTetrode](https://calcul.io/constants/sackurTetrode/index.md) | Sackur-Tetrode constant at T=1 K and p=101.325 kPa | | [secondRadiation](https://calcul.io/constants/secondRadiation/index.md) | Second radiation constant | | [speedOfLight](https://calcul.io/constants/speedOfLight/index.md) | Speed of light in vacuum | | [SQRT1_2](https://calcul.io/constants/SQRT1_2/index.md) | | | [SQRT2](https://calcul.io/constants/SQRT2/index.md) | | | [stefanBoltzmann](https://calcul.io/constants/stefanBoltzmann/index.md) | Stefan-Boltzmann constant | | [tau](https://calcul.io/constants/tau/index.md) | | | [thomsonCrossSection](https://calcul.io/constants/thomsonCrossSection/index.md) | Thomson cross section | | [true](https://calcul.io/constants/true/index.md) | | | [vacuumImpedance](https://calcul.io/constants/vacuumImpedance/index.md) | Characteristic impedance of vacuum | | [weakMixingAngle](https://calcul.io/constants/weakMixingAngle/index.md) | Weak mixing angle | | [wienDisplacement](https://calcul.io/constants/wienDisplacement/index.md) | Wien displacement law constant | [All constants](https://calcul.io/constants/index.md)