To ensure maximum device current is supplied through a vertical device having a backside ohmic contact, the specific contact resistivity, ρc, must be well characterized as it constitutes a portion of the device resistance. While there are multiple approaches to deduce ρc, the transmission line model (TLM) remains a convenient choice because of its simplicity in terms of fabrication, measurement, and analysis. For thick substrates where mesa isolation is impractical, the circular transmission line model (CTLM) is an attractive path. In this study we propose an additional restriction on the CTLM design such that the ρc is readily extracted from a simple linear regression just as is the case in a normal TLM. We demonstrate the simplified method by extracting ρc of an ohmic contact to the c-face of 4H-SiC substrate.