The study and analysis of enzymatic reactions are essential for characterizing various biological systems. As part of these procedures, it is important to understand how to quantify the biological activity of these proteins in terms of enzymatic activity. This work proposes a general equation for determining enzymatic activity based on experimental data, along with the theoretical elements that support it. A model exercise is included, and the methodology for calculating both enzymatic activity and specific enzymatic activity is outlined in detail, step by step. This procedure is specifically designed for undergraduate students in the biological sciences who are interested in enzyme kinetics.