This work tries to close the gap between continuous synthesis, measurement, calibration, and analysis on R&D scale. By introducing new calibration methods, the full potential of inline ATR‐FTIR spectroscopy in continuous reactor setups is unraveled. A fast, fully automated calibration of the reaction mixtures is carried out at process conditions. The use of different compositions underlines the robustness of this calibration method, which was used for the determination of kinetic parameters. The conversion‐based calibration significantly increased the precision of the analysis. In difference, the new method only requires the preparation of two calibration mixtures. By that, this method can also be applied to large‐scale processes and allows the use of a single measurement setup from R&D to industrial scale.