Currently, cities use their waste diversion rate as a tool to measure the performance of their waste management systems. However, diversion of waste from landfill does not give a holistic picture of zero waste performance. This paper conceptualises the concept of the ‘zero waste city’ and proposes a new tool to measure the performance of waste management systems called the ‘zero waste index’. The zero waste index forecasts the amount of virgin materials, energy, water and greenhouse gas emissions substituted by the resources that are recovered from waste streams.