The debt-to-income Ratio (DTI) is how much money you earn versus how much you spend monthly. It is calculated by dividing your monthly debts (not necessarily all expenses) by your gross monthly income before tax.

For the purpose of calculating your DTI, include monthly payments for minimum payment Credit Cards, Car Loans, student loans, and any other loans or obligations you pay every month. This does not include the housing expenses such as utilities, groceries, clothing, etc.

Add the expected monthly mortgage payment, including the Principal, Interest, Property tax, and hazard Insurance, known as PITI.

Add other monthly fees related to the mortgage, such as monthly Home Owner Association fee (if it exists) and monthly Mortgage insurance premium, etc.

For Credit card payments, only add up your minimum monthly payments (even if you pay extra).

For a Student loan, if you are not set on how much you have to pay every month, use 1% of the loan balance.

Example of calculating a DTI:

Let's say you are working 32 hours per week at an hourly rate of $45. Your current balance on your credit card is $1024, with a minimum payment of $40. No car payment, $40 HOA/month, and you are paying $2700 for monthly payments, which include PITI and MI.

Your Monthly gross income = 32 hours/week*$45*4 weeks/month + 16 hours/3 days * $45 =$6,480 per month

Your DTI will be ($2700+$40+$40)/$6480 = 42.90%, which is fine.