If you pull a three beur., credit report it will show all your debt and monthly payments. this is what a lender looks at. All the monthly payments on the credit report. This Would be added to the respective new monthly payment, taxes and insurance of your new loan as a percentage of your gross monthly income.
There are two ratios. The top will be the percentage of your new mortgage, property taxes and insurance on a monthly basis of your gross monthly income.
The bottom ratio will be this plus all other monthly debt.
28% is great, 40% is somewhat harder, 50% is almost the end.
Of course this all do's not matter if you have great credit scores and go Stated. In this case you just say how much you make a month.
If you are still in school or taking courses etc. then the shool loans do not count. You would have to get a letter from the school etc. that you are still going.