In this study, scale effects on the hydrodynamic performance of DTMB 4119 propeller have been investigated in uniform flow under non-cavitating and cavitating conditions by a simple practical method based on OpenFOAM. A potential based Lifting Surface Method has also been applied. A verification study of non-cavitating simulations has been carried out by Grid Convergence Index method at one scale ratio. Then the results have been validated with experiments. Schnerr-Sauer cavitation model of OpenFOAM has been used for the phase change between vapor and liquid. Cavitation simulations have been performed as a time-dependent with dynamic mesh while non-cavitating simulations have been carried out as a steady-state with static mesh. Effects of the scale ratio and cavitation simulations have been investigated and a simple fitting procedure on the thrust and torque values based on logarithm of Reynolds number have been applied. Results have also been compared with ITTC corrections.