As the design process of a wind turbine blade is highly iterative, one needs to do the same calculations several times. During that process, the kind of structural model use must be chosen carefully trying to obtain a good compromise between precision and model setup and computation time. This paper compares four blades structural models of different levels of complexity. These models are compared to each other and with experimental results with respect to their abilities to analyze blade cross-sectional properties, natural frequencies, deflection, strains, buckling strength and composite strength. This comparison shows that even if the 3D shell finite element model is the more precise and is the only one that can manage the regions of the blade where the cross-sectional shape changes quickly, models based on strength of material models give accurate results. Even the simpler model, based on blade shape simplification, gives conservative and accurate results at a very low computational cost.