In the last few years, the application of quantitative methods in the field of use wear analysis has grown considerably, involving the use of different techniques. A development in surface measurements approaches has become necessary as standard assessments based upon qualitative functional analysis are often affected by a degree of subjectivity and a limited reproducibility. To advance the current methodological debate on functional analysis of ground stone technology, we present a combined methodological approach, including qualitative and quantitative analyses, applied to the study of experimental sandstone ground stone tools. We test surface quantification at a macro and micro-scale, paired with the observation and description of residue and use wear connected to the processing of plant, animal and mineral matters. Our results provide an exhaustive quantitative dataset concerning surface modifications associated with different uses and suggest an analytical workflow for the functional analysis of both experimental and archaeological ground stone assemblages. We also highlight the limitation and pitfalls of an exclusive adoption of quantitative methods in the study of ancient tool use demonstrating how a synergetic approach can enhance the quality, reproducibility and comparability of functional data.