This paper presents the effect of hull roughness over 10 years of operation on ship performance. The numerical model is developed by coupling NavCad and Matlab to perform the computation and the data processing. On the basis of a given hull, an engine, and an optimized propeller, the performance of the ship is computed for eight cases of hull roughness according to the ITTC recommendations in both calm waters and different weather conditions along the ship route. The effect of both wind and waves is considered for computing the added ship resistance along the route, thus requiring more power than just only the added resistance in waves. This provides a more accurate estimation of the ship’s performance along the different sea states. Lastly, a weighted average of the main ship parameters is estimated to evaluate better the ship’s performance. According to this study, the fuel consumption in calm water can be increased by around 20% after 10 years of ship operation based on the level of hull roughness. However, in the same weather conditions along the ship route, the ship’s fuel consumption can be increased by 10% compared to the same trip with a clean hull.