The coronary artery is numerically investigated based on CFD techniques for measuring the severity of stenosis. In mild cases, medication is often preferred whereas for severe cases surgical intervention is 'required but most of the cases fall in between. Thus, it poses a problem for clinicians in choosing an appropriate action. The Fractional Flow Reserve (FFR) is a number which helps to predict the functional significance of stenosis in this scenario. In this study, various cases of occlusion percentranging between 40 to 70 are considered using different models for predicting FFR in the stenosed coronary artery. The lesion length is also varied between 1 cm and 5 cm based on patient-specific data. The experimental investigation of FFR in the coronary stenosis using silicon model is also carried out in this study and compared with numerical results. The effect of occlusion percentage and lesionlengthon the FFR value are quantified. © The Authors, published by EDP Sciences, 2019.