In the field of carbon footprints we have seen how detrimental can be the absence of shared definitions and calculation methods. One common language is crucial, otherwise it is difficult to share information about actual footprints and reduction targets. Many individuals and organisations have asked the Water Footprint Network for a manual that contains a complete, consistent and up-to-date overview of the method of water footprint assessment. For this purpose, the network has produced the Water Footprint Manual. The document covers a comprehensive set of methods for water footprint accounting. It shows how water footprints can be calculated for individual processes and products, as well as for consumers, nations and businesses. Besides, the manual includes methods for water footprint sustainability assessment and a library of water footprint response options.