The calculators are potential tools to show the order of magnitude of actions (e.g. the importance of energy use at home), and help motivated people to focus their efforts on high impact actions. Calculators can also include features, informational or social, aimed at encouraging users to take action. We highlight good approaches and features of carbon footprint calculators and interventions. At the same time, we discuss the shortcomings of existing approaches. Based on the examined calculators, literature and our experience as a calculator developer and a host, we make recommendations about calculator development and use in interventions aiming to reduce consumption footprint.