Many ports around the world are threatened by sea ice. Access by merchant ships to these ports is ensured by ice-breaking services. For the sensitivity of calculations of the amount of cargo on vessels carrying out loading and discharging in waters covered with ice, the calculations need to be modified. This study aims to investigate the effects of sea ice in different thicknesses on the calculations of the cargo amounts, especially the effects on the tonnage per centimeter (TPC) values of the vessels. There is a limited number of studies on ice resistance of zero-speed vessels. An experimental study was performed to gauge the impact of ice on vessel draughts on a scale ship model. The scaled TPC weights were applied under two separate loading conditions on the scale model ship. Such processes were repeated for various ice thicknesses. The results indicated that an increase in TPC values was in a linear relationship with ice thickness and was found under both loading conditions. In analyses based on the scale model according to the draft marks, the ice friction created an overloaded case. In the stability booklets, it is assumed that adding the amount of increase in TPC value as a correction would resolve disputes over the amount of loaded cargo and can circumvent overloading cases.