Waste of electric and electronic equipment (WEEE) contains both hazardous and valuable materials. The European directive on WEEE gives producers and importers of EEE the responsibility to collect and treat WEEE. In order to evaluate the effectively of collecting schemes, it is necessary to know the quantity of WEEE generated. The purpose for this project has been to establish a method to measure amount of WEEE generated. It has also been developed a practical Excel model to demonstrate the method. The model is based on amount of EEE supplied to the market and the lifetimes of the products. The report describes in detail the development work and shows examples of calculation. The Excel model is available for documentation and demonstration, together with a user guidance. The project joint venture and Nordisk Council of Minister disclaim responsibility for how users might use the tool and its results.