Equal channel angular pressing (ECAP) is a widespread severe plastic deformation (SPD) method to fabricate ultrafine-grained bulk materials. In the field of materials engineering, this method has already experienced rapid development over the past few decades. In this research, the authors sought to create a prediction of shortening and the material particle size after extrusion using ECAP. Behaviours of essential functions are analysed here on samples of pure copper Cu 99.9. It is the measurement and analytical processing of changes in the values of selected structural and mechanical parameters depending on the reduction of the structural granularity. Parameters such as deformation speed, deformation work and ECAP mechanical performance are also included in the results. The change in structure and mechanical parameters is also newly demonstrated by measuring the change in the velocity of the longitudinal ultrasound wave during the experimental passes. Based on the results obtained, new computational algorithms for Excel and Matlab were developed. The algorithms developed here contain many new findings, conclusions and derivations addressing the integrity of the surface with the inner structure of materials. Algorithms are very well-suited for obtaining results on different materials quickly, for predicting and checking measured values, and for designing optimal measurement technology parameters for the ECAP method.