Given the diameter, free height, and length of a cement mill, this document outlines the calculations to determine: the radius and total volume of the mill; the height from the surface to the center; the angle and area produced by a ball covering the periphery; the base and area of the resulting triangle; the cross-sectional area of the ball-covered mill; the volume of the ball-filled mill; and the percentage of mill filling. These calculations provide insights into the geometry and filling of a cement mill based on its key dimensional properties.