Gibbs free energy calculator


The Gibbs free energy is a thermodynamic potential that measures the “usefulness” or process-initiating work obtainable from a thermodynamic system at a constant temperature and pressure (isothermal, isobaric). When a system changes from a well-defined initial state to a well-defined final state, the Gibbs free energy ΔG equals the work exchanged by the system with its surroundings, minus the work of the pressure forces, during a reversible transformation of the system from the same initial state to the same final state.

Related formulas


GFree energy (J)
UInternal energy (J)
pPressure (Pa)
VVolume (m3)
TTemperature (K)
SEntropy (J/K)