Conventional Coulter counters have been introduced as an important tool in biological cell assays since several decades ago. Recently, the emerging portable Coulter counter has demonstrated its merits in point of care diagnostics, such as on chip detection and enumeration of circulating tumor cells (CTC). The working principle is based on the cell translocation time and amplitude of electrical current change that the cell induces. In this paper, we provide an analysis of a Coulter counter that evaluates the hydrodynamic and electrokinetic properties of polystyrene microparticles in a microfluidic channel. The hydrodynamic force and electrokinetic force are concurrently analyzed to determine the translocation time and the electrical current pulses induced by the particles. Finally, we characterize the chip performance for CTC detection. The experimental results validate the numerical analysis of the microfluidic chip. The presented model can provide critical insight and guidance for developing micro-Coulter counter for point of care prognosis.