The masterʹs thesis is divided into 7 chapters. In the introductory part of the thesis, the importance of defining the light ship mass in the preliminary phase of ship design is stressed. The light ship mass is determined for three types of merchant ships: bulk carriers, container ships, and tankers. For each type of merchant ship, a data base of 110 ships was created containing the most important features of the ship, which is shown in Chapter 2. The shipbuilding journal Significant Ships served as a source of data. To determine the interdependence of individual features, a regression analysis was performed. The results of the regression analysis are presented in the scatter plots and the corresponding regression equations. The ship form coefficient that most influences the resistance of the ship, and is determined in the preliminary phase of the ship's foundation, is the block coefficient. For each type of ship, the block coefficient was calculated in the third chapter according to various empirical methods and was compared with the values obtained from the journal Significant Ships. Calibration was performed for the method that showed the smallest deviation of the results. In the fourth chapter, a data base of dimensionless forms in the computer program GHS (General Hydro Statics) for the ranges of the block coefficient from 0.50 to 0.85 was created. The hydrostatic characteristics of the forms are shown in the form of the table. Chapters five and six represent the main part of the thesis. The most complex feature that a designer needs to determine in the early stages of shipbuilding is the lightship mass. Therefore, in the fifth chapter, a list, and analysis of available methods based on empirical data of built ships, for estimating the lightship mass for a particular type of merchant ship is done. In Chapter six, lightship masses are calculated using empirical methods. The values obtained were compared with the values of the light ship masses given in the journal Significant Ships. As with the calculation of the block coefficient, for the method that showed the smallest deviation of the results, calibration was performed. At the end of the paper, a conclusion is given.