This study focused on the modelling of corrosion rate of the water distribution network of Patna, (Bihar), India using Design Expert 13 software. A total of nine variables, including pH, temperature, total dissolved solid (TDS), alkalinity, calcium hardness, chloride, sulphate, dissolved oxygen (DO), and time, were considered for modelling. The physicochemical parameters were determined through regular monitoring of water samples. The corrosion rate was determined by direct monitoring of water distribution pipes using adjustments of seven GI coupons for 45, 90, 135, 180, 225, 270, and 315 days. Modelling was performed using the low level and high-level experimental range for pH, temperature, TDS, alkalinity,