A rotary cutting tool has a central, longitudinal axis. One or more internal balancing features are disposed within a cavity of the rotary cutting tool. Each internal balancing feature includes a balancing mass suspended within the cavity by a spring-like element, and an adjusting screw for effecting radial movement of the balancing mass. Each internal balancing feature can be integrally-formed with the rotary cutting tool using a 3-D printing technique. The rotary cutting tool can be any rotary cutting tool, such as a milling cutter, a boring bar, and the like. The internal balancing features are arranged at predetermined locations within the rotary cutting tool to enable static and/or dynamic balancing of the rotary cutting tool.