The proceedings volume contains the selected papers presented at the 15th Symposium of Magnetic Measurements and Modelling SMMM'2025, which was held in Siewierz (Poland), September 15–17, 2025. The Symposium was organized by the Częstochowa Branch of the Polish Society of Theoretical and Applied Electrical Engineering (PTETiS) in cooperation with the Faculty of Electrical Engineering of the Czestochowa University of Technology, the Institute of Metrology, and the Poznań Branch of PTETiS. 
 
The Symposium emerged in 2011 as a continuation of the previously held Symposia of Magnetic Measurements. 
 
The 15th Symposium of Magnetic Measurements & Modelling provided an excellent opportunity for scientists and engineers involved in magnetic measurements and the modelling of magnetic properties to present and discuss their research results. The scope of the Symposium has been broadened to include both the modelling of the properties and the applications of magnetic materials, thus covering the following subjects: measurements of magnetic quantities, indirect determination of physical quantities using magnetic measurements, measurement techniques in high-frequency range, nondestructive evaluation of materials, modelling of magnetic properties, magnetocaloric and magnetomechanical effect, structure and properties of magnetic materials, sensors and actuators, magnetic circuits in electrical machines, and mechatronics systems. 
 
Over 45 people from domestic and abroad academic centres, research institutes, and industry participated in the Symposium, including representatives from the following institutions and enterprises: Brno University of Technology (Czech Republic), Brockhaus GmbH & Co. KG (Germany), Helmut Schmidt University/University of the Federal Armed Forces Hamburg (Germany), Megger Instruments Ltd. (United Kingdom), Pavol Jozef Šafárik University in Košice (Slovakia), RWTH Aachen University (Germany), University of Kragujevac (Serbia), University of Lyon (France), Stalprodukt S.A. (Poland), Technical University of Košice (Slovakia). 
 
During the Symposium, 7 sessions were organized and 32 presentations were given, including two invited talks in the plenary session delivered by:

• • Benjamin Ducharne, "Modeling magnetic losses in soft ferromagnets: A viscoelastic approach using fractional derivatives" (University of Lyon, France) — see picture 1,
  • Piotr Gębara, "Magnetocaloric effect and its applications" (Czestochowa University of Technology, Poland) — see picture 2.

 The Chairmen of the Organizing and Scientific Committees would like to express their gratitude to all participants for presenting their research at a high level, addressing scientific and engineering aspects related to the measurements and modelling of the properties of soft magnetic materials.

Mariusz Najgebauer
Krzysztof Chwastek

Editors of the Proceedings