A new turbomachinery design system, T-AXI, is described and demonstrated. It is intended primarily for use by educators and students, although it is sophisticated enough for actual designs. The codes, example cases, and user's manual are available through the authors' websites. The design system can be used to design multistage compressors and turbines from a small number of physical design parameters. Students can understand the connection between these physical parameters such as the Mach number and flow angles to the cross sectional area and angular momentum. There is also a clear connection between the angular momentum, work, and blade loadings. Loss models are built-in and results are compared against tested geometries. The code also has a built-in blade geometry generator, and the geometry can be the output for running the MISES blade-to-blade solver on each section or visualizing the blades. A single stage compressor from the U. S. Air Force Stage Matching Investigation rig, the 10 stage NASA/GE EEE high pressure compressor, and the NASA/GE EEE 5 stage low pressure turbine have been used to validate T-AXI as a design tool. [DOI: 10.1115/1.4001240]