This paper presents a fast and accurate way to design and optimize LC oscillators using the inversion coefficient (IC). This methodology consists of four steps: linear analysis, nonlinear analysis, phase noise analysis, and optimization using a figure of merit. For given amplitude of oscillation and frequency, we are able to determine all the design variables in order to get the best trade-off between current consumption and phase noise. This methodology is demonstrated through the design of Pierce and cross-coupled oscillators and has been verified with BSIM6 metal oxide semiconductor field effect transistor compact model using the parameters of a commercial advanced 40 nm complementary metal oxide semiconductor process.