Abstract
The objective of this study is to develop a system to determine optimal machining conditions for minimizing energy consumed in machine tools. To realize this objective, we developed a module calculating the cutting energy and energy consumed in each unit comprising a machine tool, and applied it in experiments. The cutting energy was calculated using cutting force, torque of cutting force, and cutting power for square end milling and ball end milling. The energy consumed by each unit of the machine tool was also estimated through experiments based on real machine tools.