Personal Inflation Calculator

Making inflation understandable for citizens

In a joint project with the German Federal Statistical Office, the University of Ulm has added an explanatory component to its Personal Inflation Calculator application, thus addressing the need for citizens to better understand the impact of inflation on their own lives.


With the Personal Inflation Calculator, the Federal Statistical Office operates a tool that allows users to calculate a personal inflation rate based on individual monthly expenditures in various categories. These personal effects have become more explosive for citizens, especially since the rising price of energy against the backdrop of the war in Ukraine. Thus, the Personal Inflation Calculator offers a targeted point of contact, but can lead to excessive demands. For example, the underlying calculation method is not easy to understand for many users and appears as a "black box".

This gap in understanding was closed by adding a user-centric, automated explanation component for the Personal Inflation Calculator: By expanding the application, users now receive corresponding explanations in addition to their personal inflation rate. These explanations show, for example, why the personal inflation rate is higher or lower than the official rate and what the personal inflation rate would be if spending behavior had changed. This means that users can now not only obtain low-threshold and individual information about their inflation rate, but also receive comprehensible and transparent explanations.

The effect of the automated explanation component was tested in user studies including A/B: For this purpose, study participants were randomly divided into two groups - a control group that used the original Personal Inflation Calculator without the explanation component, and a treatment group that used the enhanced Personal Inflation Calculator.

Cooperation partner: German Federal Statistical Office

Project period: July 2022 - November 2022



The results demonstrate the effectiveness of the automated explanation component on the user experience. Users of the enhanced personal inflation calculator find it more user-friendly and useful than the original version without the explanation component. Perceived self-efficacy also increases: users feel more able to exert a self-determined influence on their personal inflation rate in the future. They value the application and show a greater willingness to use it in the future, as well as a higher level of trust in the personal inflation calculator, which has been expanded to include the explanatory component.