Your home buying power is a holistic view of how much house you can afford. It factors in all your income (including base income, bonuses, tips, investment dividends, rental income, etc.) and how much you have saved for a down payment and weighs it against your current debt. To calculate your buying power, add up all your pretax income. You can typically afford to spend 28 percent of your annual income on all housing costs (this includes property tax, utilities, and HOA fees). However, your total debt (including mortgage, car payments, student debt, and credit cards) shouldn’t exceed 36 percent of your income, so if you have a lot of other debt, your home buying power is reduced.