Flag your financial goals and then plan to achieve the target. Use this calculator to ascertain how much money you should save every year at a particular interest rate to achieve your down payment at the time of buying the house. If you want to buy a house that will cost Rs 1 crore after five years, this calculator will let you know how much you should save every year at a particular interest rate to reach the down payment. For outright purchase, the down payment will be the entire cost of the house.