The objective of this research is to introduce a numerical simulation model to predict approximate values of the matric suction inside unsaturated soils that have low water contents. The proposed model can be used to predict the relationship between the water content and the matric suction of a studied soil to construct the soil-water characteristic curve. In addition, the model can be utilized to combine the predicted matric suction with the soil parameters obtained experimentally, which enables us to explain how matric suction can affect the behaviour of unsaturated soils, without the need to utilize advanced measuring devices or special testing techniques. The model has given good results, especially when studying coarse-grained soils.