The method of isothermal heat flow calorimetry delivers precise information on the kinetics of cement hydration. Consequently, the method is also sensitive to mechanistic changes in the hydration process caused by adding retarders or functional additives in general. The quantification and collection of retardation parameters allow us to systematically compare both the efficiency of different retarders and, at the same time, the influence of the retarders on the hydration mechanism. While it is beyond the scope of this work to dive deeper into the mechanism of retardation, the presented method allows for a systematic comparison. Furthermore, the method is not limited to the study of retarders but can be applied to any functional additive that influences the hydration kinetics of cement. As outlined in the introduction, different methods have been reported to quantify the induction time of cementitious systems. We have shown that t is , t AST M , and t a are mathematically precisely defined and are straightforward to obtain from heat flow calorimetry data. On the other hand, determining the time of maximum heat flow t max is more problematic due to the interference of the sulfate depletion peak. Finally, we presume that the tedious manual analysis can explain the scarcity of quantitatively analyzed calorimetry data in the literature. This work provides a simple and robust method to determine characteristic times and corresponding physical values from isothermal calorimetry data. This method can provide reproducible results for hundreds of calorimetry curves in seconds or minutes.