In case of columnar supported embankments, the settlement difference at the embankment surface between the soft soil and the column region can be observed due to the stiffness difference between them. The differential settlement at the embankment surface decreases as the height of the embankment increases due to the mobilization of shear stress within the embankment soil. For columnar supported embankment, the minimum height required to maintain no differential settlement at the embankment crest can be referred to as the critical height of the embankment. In the present study, three-dimensional unit cell model is developed using FLAC3D software to determine the critical height of the embankment resting on floating stone column-reinforced soft soil. The Mohr-Coulomb model is used for sand embankment and stone columns, whereas the soft soil is modelled using Modified Cam-Clay model. The results of the present study are compared with the field data. The influence of the elastic modulus of the stone columns on the critical height is studied. Findings indicate that for floating stone column-supported embankments, an embankment height exceeding 2.5 times the column spacing is needed to avoid any significant differential settlement at the embankment surface.