The deflections appeared by cutting forces in ball end milling of inclined surfaces can result in defects in workpiece. Finding deflection values has a significant importance for keeping the production within the appropriate tolerances and in lessening production costs. The aim of this study was to evaluate tool deflection values experimentally, analytically, and numerically depending on cutting force in ball end milling of inclined convex and concave surfaces of DIN 1.2344 using TiN-coated cutting tool. The experiments were conducted with different cutting tools strategies and cutting parameters at related parameter levels. During machining, real time cutting tool deflections were recorded by inductive sensors for the experiments. In analytical studies, tool deflections were calculated depending on cutting force using cantilever beam method. In numerical studies, the solution was made with the finite element method. In the implementation of this method, commercial finite element software ANSYS was used. As a result, the values of tool deflections measured experimentally were found to match closely with analytical and numerical studies. The most effective parameters within the selected cutting parameters for both inclined surfaces were found step over and feed rate. At the same time, the measurement of dynamic deflection with inductive sensors was found to be beneficial for three-axis milling operations.