So if you make 3,000 a month, you can spend .28 of it, or $940 on a mortgage payment or .36 of it, or $1080, on mortgage and other debts. You typically need to keep below both of these ratios.
These are guidelines lenders follow when deciding whether to lend to you. These ratios go up and down depending on your credit rating, and how long and stable your employeement is, and other assets you might have. They also vary between different kinds of programs-- convential, VA, FHA.
Even if you have poor credit and no cash in the bank but you and your spouse earn good saleries and have stable jobs, you can qualify for a loan. In fact modern lending will lend to just about anyone but they will charge you more for it -- more to originally get the loan, more interest rates, more restrictions on what you can do once you have the loan. Just because some will lend to you is not a good reason to taking the loan.
See the web resource page on this web site for some online home finance calculators: Web resources