Copper is one of the most widely used industrial metals, which has a good weldability by fusion methods; but the grain growth is one of the problems that occurs in heat affected zone of this metal causing the decrease of mechanical properties of the joint. To calculate the grain growth, first of all, it is needed to fit the experimental data to mathematical models and calculate the existing parameters. In this research, the grain growth of commercially pure copper has been studied. For this purpose, the samples of copper sheet were isothermally held in furnace at the temperatures of 1123, 1173 and 1223 K for the times of 10 to 60 minutes. The average grain size was determined from the metallographic image analysis and the 2D grain size was converted to 3D grain size through the computational methods. Sellars and Anelli models were used to fit the data, and grain growth parameters were obtained for both models. The analysis of the normalized residuals showed that the mean is close to zero and they have a Gaussian distribution, and both models seem to fit reasonably to the data. Mechanical properties were measured by microhardness test and tensile test. It was observed that the relationship between hardness and yield strength with grain size follows the Hall-Patch relationship and the corresponding constants were obtained.