Numerical simulation is of interest for most fan designers to optimize the fan designs. Computational fluid dynamic (CFD) has become an essential tool in almost every branch of fluid dynamics and one of the major tools for fan designs. As the fan designers relying on the numerical simulation, the accuracy of tools such as CFD in predicting the performance has become a subject of interest. This paper validates the CFD modeling of an axial fan design against experimental result. The experimental rig and test procedure are developed with reference to "AMCA standard 210". The analysis is conducted on 1250mm diameter axial fan with two different blade pitch angle 30° and 40°. Prior to encounter the swirling effect and deflection of velocity vector due to rotor blade, a stator blade with the same profile as rotor blade is used as the outlet guide vanes in opposite direction. The computational model is created according to the experimental condition and applied realistic boundary conditions. The model is simulated using commercial CFD package, ANSYS FLUENT. The results obtained are compared against experimental data (AMCA standard 210) over wide range of flow rate. Provided the modeling strategy is chosen appropriately with correct configuration of mesh density and turbulent model then, the results correlates closely with experimental data. This is shown in this investigation. The guide vane incidence angle determination is also done in this paper for 30° and 40° blade pitch angle. The outcome of this paper would provide confidence for designers in numerical simulation for predicting performance of axial fan. In addition, numerical simulation creates a platform for systems to be optimized with a lower cost and high efficiency outcomes.