In this session, we will launch the ISWA publication: Assessing Circularity in Cities, a Handbook. The Handbook is a compilation of the lessons learned during  the three-year Circular and Low Carbon Cities (CALC) project of the ISWA working groups WGRWM and WGCCWM. A key ambition of the project has been to find a way to provide practical methods for cities to give “hands and feet” to the somewhat vague concept of a “circular economy” within their boundaries. The  Handbook provides practical instructions for city staff and consultants to investigate, and quantify, via modelling, the contribution of private circular processes within the city boundary to city circularity. In the Handbook the reader will find step by step instructions for identifying these processes, and a quantitative methodology for modelling their availability, the intensity of their use, and their impact. The authors handle the “low carbon” aspect by modelling the contribution of circular processes to extending useful life of products and materials, and provides algorithms for calculating and modelling avoided extraction and production impacts. The Handbook provides practical guidance in 12 steps, for researching circularity in cities, and creating an annual benchmarking moment. By incorporating the Handbook into annual monitoring, cities can track over time, their progress to becoming more circular.