This discussion clarifies the calculation of interest under Section 50 of the GST Act. It explains that interest for late payment is charged at 18% per annum on the net amount payable (after deducting eligible ITC). For excess claimed ITC, the interest rate is 24% per annum. The calculation formula provided is: Interest = (Payable Amount) x (Rate of Interest) / 365 x (Number of Delayed Days).