Reinforced thermoplastic pipes (RTPs) are increasingly used in onshore and offshore oil and gas production industries owing to their lightweight and resistance to corrosion and pressure. Accurate estimation of pipe stiffness (PS) is crucial in onshore engineering. Further research is needed to define the properties of the parameters affecting stiffness. This study investigates the estimation of the stiffness of RTPs under transverse loads, incorporating analytical, numerical, and experimental research methodologies. Additionally, the influence of winding angle, thickness of the reinforced layer, and thicknesses of the liner and cover on the stiffness of the RTP is evaluated and discussed. To achieve this objective, a detailed analysis of composite pipes with external diameters of 90, 200, and 323 mm and wall thicknesses of 14.2, 16.6, and 13.6 mm, respectively, was conducted. These analyses involved the implementation of multiple diameter verification procedures to ensure the accuracy and reliability of the results. In analytical and numerical studies, a layered composite modeling approach has been adopted for RTPs. Consequently, isotropic and anisotropic material properties have been defined for each layer. The studies show that the thickness and winding angle of composite tapes significantly contribute to the stiffness of the pipe, whereas the thickness of the liner and cover is less effective. Additionally, increasing the winding angle to 90° significantly improved the PS. The findings provide a reliable and efficient method for calculating the stiffness of pipes under transverse loading. This method can be utilized during the design stage to simplify the design process for RTPs. A comprehensive evaluation of PS using a layered modeling approach enables researchers to make informed decisions regarding the use of thermoplastic composite tapes for piping applications. This approach can also be used to maximize pipe performance under various stiffness scenarios.