A brief review of the estimation of measurement uncertainty is given in the context of the measurement of solubilities and related thermodynamic parameters. Evaluation of measurement data - guide to the expression of uncertainty in measurement (known as the GUM) is the definitive treatise which uses a 'bottom-up' approach. However grouping components of measurement uncertainty with repeated independent measurements is encouraged. Examples are given of the measurement of solubility of oxygen in nickel-iron alloys, the solubility of whitlockite and the solubility of cadmium carbonate in aqueous systems. (C) 2019 Elsevier Ltd.