Abstract <p>The article is devoted to the development of an original approach to determining the value of the surface energy of metals and products made from them. A method has been developed for determining the value of surface energy based on measuring the contact potential difference, taking into account the surface hardness of the metal being studied. A machine learning model has been developed that allows the gradient boosting method to calculate the value of the surface energy. A practical example shows the application of the developed method for determining the value of the surface energy of parts made of structural and tool steels and alloys.</p>