A person is in 30% tax bracket. His company has deducted correct tax for the income he has gained from salary. For financial year 2011-12 the person has earned 96000 as property income (rent) , 20000 as short term gain from selling shares. There is no loan on him. Unfortunately the person has not paid any advance tax. Now while filing tax return some penalty / interest on this total taxable income is applicable as the person has not paid any advance tax. I am interested to know how this penalty is calculated.