In most bio-impedance applications, measurements are collected from a single electrode configuration though multi-electrode systems could monitor different tissue sites or serve as a source of redundancy in case of electrode malfunction. However, comparison of impedance data collected from different electrode configurations is difficult. This article proposes an approach to estimate the current tissue impedance collected from a fixed electrode configuration using measurements from different sites of the same localized tissue. Estimated impedance is calculated using the ratio between impedance values from different electrode configurations collected prior to the electrode malfunction event. This approach is validated using measurements of a human forearm collected from 3 kHz to 1 MHz collected with 4 electrode configurations over 3 days. The estimation results using this approach show maximum estimation errors of 2.3% and 16.9% for the resistance and reactance, respectively, compared to the measured impedance.