Environmentally friendly fuels are increasingly becoming a binding necessity along with policies to reduce global emissions. Natural gas is a promising fuel for marine transportation. The small-scale LNG carrier is one of the carrier ships designed for distributing natural gas in inland and shallow waters. The purpose of this study is to determine the optimum dimensions SSLNG with three parametric designs of cargo load conditions, i.e., 2500 m^3, 5000 m^3, and 7500 m^3. The spiral design theory has been used to optimize 3 particular parameters of ships, i.e., volume, mass, and linear dimensions. The design criteria is determined based on the statistical data from existing smallscale LNG carrier dimensions from all over the world. As a case study, two shipping destinations were used to supply power plants in remote areas with shallow water conditions. The result of optimum dimension from the analytical approach obtained the main dimensions of small-scale LNG carrier 2500 m^3 are length overall 81.5 meters, beam of 14.2 meters, and draught of 4.8 meters. This optimum ship dimension is suitable for serving shallow water conditions. Further findings in this research are that the dimensional ratio criteria for small-scale LNG ships vary depending on the cargo volume to be designed.