Modern engineering challenges require the world to use renewable and environmentally friendly energy. One of the most important forms of renewable energy is solar energy. The parabolic collector is a popular collector used to absorb solar energy. In this study, a new approach is used to calculate the radiation concentration ratio in a parabolic collector. The concentration ratio is calculated from the ratio of the reflection beam to the incident beam radiation, and it depends on two main variables: the collector width (W) and the focal length (P). The model is tested and compared to results from previously published work. The comparison showed that the model results can be relied upon for accuracy and are compatible with published results. The results indicate that increasing the width of the collector (W) leads to an increase in the concentration ratio (RC), while the contrary is true when the focal length (P) increased. The collector efficiency minimum values were 19.3%, 21.07 %, 22.35% and 23.33% at concentration ratios of 69, 80, 103 and 148 in line with the focus length values of 0.6m, 0.7m, 0.8m and 0.9m, respectively. The developed model is applied according to the conditions of Basra, Iraq (47.78o longitude and 30.5o latitude).