Accurate K_DP estimates are crucial in radar-based applications. We quantify the uncertainties of several publicly available K_DP estimation methods for multiple rainfall intensities. We use C-band weather radar observations and employed a self-consistency K_DP, estimated from reflectivity and differential reflectivity, as a framework for the examination. Our study provides guidance for the performance, uncertainties, and optimisation of the methods, focusing mainly on accuracy and robustness.