Recently, a modified mathematical model was presented in order to determine the productivity of multi-fractured shale gas wells. However, the considerable challenge of the model was assuming an average fracture width for the determination of the practical fracture geometry of the stimulated reservoir volume. This challenge led to over prediction of the gas well. Therefore, this paper presents a simple and accurate method using a pseudo-3D model to determine the fracture width in shale gas reservoirs. The method utilized the hydraulic fracturing propagation capacity of the MATLAB software to visualize the fracture geometry, which includes the fracture height, fracture length, and the fracture width. So, the obtained fracture width can be incorporated with analytical models to predict long term productivity for multistage fractured shale gas wells. An accurate result for the productivity will assist in determining the ultimate gas recovery, propped volume, optimal fracture length, fracture spacing and predict the future performance of the well. © 2022, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.