Measuring sustainable tourism at the municipal level

•Indicators are the main quantitative instruments used to assess sustainability.•Indicator system (IS) enables us to detect impacts and applying partial solutions.•IS is an effective tool for planning and managing tourism at municipal level.•IS enables managers to make sustainability an integral part of decision processes. The objective of this research is to provide a scientifically sound, applicable method for studying tourism sustainability at the local level. This is done by developing an indicator system based on an initial literature search that serves to compile a preliminary list of indicators, which are then verified and scientifically validated by conducting a Delphi survey. This process is used to develop a consensual indicator system that is adapted to the tourism sector and includes 26 indicators of social, economic and environmental sustainability. To ensure the applicability of the system, indicator values are then calculated for 20 tourism municipalities in Catalonia (Spain). The results confirm the proposed system is an effective tool for planning and managing tourism at municipal level.