Your total monthly debt, divided by gross monthly income and shown as a percentage. Total monthly debt includes monthly mortgage payments as well as student loans, car loans, and credit card payments. Example of an ideal debt-to-income ratio: If debt = ($XXX) and gross monthly income = ($XXX), the Debt-to-Income Ratio equals ($XXX) divided by ($XXX), or (XX%). This indicates that you are well qualified to pay back the mortgage loan. Generally, lenders want a debt-to-income ratio of 36% or under, although some lenders will accept ratios up to 50% if you have a good credit rating. Also called the back-end ratio or total debt ratio.