Experts suggest that you need an annual income of between $100,000 and $225,000, dependent on your financial status for the ability to purchase a $1 million house. Your ratio of debt to income (DTI) as well as your credit score, along with your down payment and the interest rate, are all factors in the amount you can afford. If you have 20% down ($200,000) and have no monthly expenses, then you are likely to be able to get the mortgage you want with a reasonable interest rate (say 30 years fixed-rate mortgage with 2.75 percent). This could bring your monthly mortgage payments to around $4,100 before other factors such as property taxes and homeowners insurance are taken into consideration. With a 20 percent down payment, average closing costs could be higher than 2%, which is you'll pay an additional $16,000 on top of the $200,000 you're making. The initial payment together with the DTI and your credit score will decide the mortgage's monthly payment.