You arrive at your income taxes due by totalling all your income, availing all applicable deductions, determining your taxable income and then calculating your taxes at rates applicable to the income slab you fall under. As a next step, if your income falls between Rs 50 lakh and Rs 1 crore, a surcharge of 10% would apply, and if your income exceeds Rs 1 crore, a surcharge of 15% would apply on taxes due. Further, 4% of taxes due (plus surcharge if any) will have to be added by way of health and education cess. If your income during a year is less than Rs 5 lakh, you are eligible to claim a rebate under Section 87A up to Rs 12,500 or taxes due, whichever is lower.