This document summarizes the design of a nine-stage transonic axial compressor. It outlines the initial design specifications, including a rotating speed of 9000 rpm, ambient pressure and temperature of 15.7 psia and 519R. It then describes the step-by-step calculations to determine performance parameters like inlet blade angle, pressure ratio per stage, overall pressure ratio, mass flow rate, and shaft power required. The results show a pressure ratio per stage of 1.145, overall pressure ratio of 2.89, mass flow rate of 66.57 lb/s, and shaft power of 4445.54 hp.