After validating both PHREEQC and Reaktoro against gas solubility measurements, further modelling is carried out to predict the bubble point pressure of geothermal fluids. The models can only be assessed against an experimental bubble point pressure measurement when the following conditions are reported: temperature, aqueous & gas compositions, GLR, and the pressure & temperature at which the GLR was determined. The measured GLR is typically reported at standard conditions (i.e., 1 atm and 273.15 K) . Only by knowing these parameters, the composition and amount of both the gas and liquid phases can be fully defined. Studies that report the entire set of conditions required for performing the modelling are, however, scarce. To estimate the bubble point pressure, we first defined the aqueous solution with a given composition. This solution was then equilibrated with a gas phase at a specific temperature and different pressures. Upon equilibration, the composition of the gas and aqueous phase changes. As pressure increases, the volume of the gas phase decreases both because of the gas compressibility and the increased solubility of the gas phase components in the aqueous solution. The pressure value that yields a gas phase volume below 1×10 -5 L (per 1 L of solution) is annotated as the bubble point pressure. In each simulation run, the pressure was increased by 0.1 bar. In PHREEQC, we defined the gas phase as a fixed pressure "GAS_PHASE" with the volume calculated from the GLR. The number of moles of gas included in the gas-liquid equilibration was then calculated internally by PHREEQC from the pressure, volume, and temperature. In Reaktoro, the number of moles of gas considered in the equilibration can be defined directly; these were calculated from the gas phase volume at standard conditions.