Debt-to-income ratio (DTI)
Your debt-to-income ratio (DTI) is your monthly debt payments divided by your monthly income before taxes. Lenders use it to decide how large a mortgage you qualify for.
New Jersey example
Say you earn a made-up $9,000 a month before taxes. A $2,400 house payment (principal, interest, taxes and insurance) is 26.7% of that. Add a $450 car loan and $150 in card payments and your total is $3,000, or 33.3%. Both are under the common 28/36 guideline, though some lenders allow higher ratios.
Official source
Everything You Wanted to Know About Buying a Home (NJ Department of Banking and Insurance)
This is a plain-English summary. Rules and dollar amounts change, so check the official source or a professional before you file or sign anything.