In this paper, a predictive (scalable) measurement-based model for high frequency interconnects on low cost FR4 substrates is proposed and demonstrated. In our research, the interconnects are modeled with equivalent circuits of scalable building blocks using a rapid and accurate optimization method to fit parameters up to 10 GHz. This predictive model then is applied for the extended structures to enhance their flexibility. The usefulness of the proposed modeling methodology is validated by comparing predictions to measurements both in frequency domain and in time domain. The speed and accuracy of the method also are compared with the Advanced Design System's momentum simulation tool. The results show that this proposed modeling for the high frequency interconnects are efficient and accurate compared to the momentum simulation. © 2005 IEEE.