Lenders also use your financial information to figure out two, very important ratios: the debt-to-income ratio and the housing expense ratio.
Many lenders use a rule of thumb that the amount of debt you are paying on each month (car payment, student loan, credit card, etc,) shouldn’t exceed more than 36 percent of your gross monthly income. FHA loans are slightly more lenient.
Housing Expense Ratio
It is generally difficult to obtain a loan if the mortgage payment will be more than 28 to 33 percent of your gross monthly income.