We propose to investigate the size-e↵ects on the surface tension calculated with coarse-grained (CG) models. We investigate di↵erent liquid-vapor (LV) and liquid-liquid (LL) interfaces with the MARTINI forcefield and orignal CG models designed for the dissipative particle dynamics (DPD) and multibody particle dynamics (MDPD) simulations. We also test a realistic CG potential developed for the DPD method to investigate the LV interface of n-pentane. Concerning the MARTINI forcefield, we observe a weak oscillatory e↵ect of the interfacial tension with the surface area for the LV interfaces of n-octane and water. This weak dependence of the surface tension with the box dimension is also observed in the LL interface of n-octane-water (MARTINI, DPD) and in the LV interface of water with the MDPD model.