
01Total Your Monthly Debt
You can calculate your debttoincome ratio by dividing your monthly income by your monthly debt payments.
DTI = monthly debt / monthly income
The first step in calculating your debttoincome ratio is determining how much you spend each month on debt.
To start, add up the amount of your monthly debt payments, including the following:
 Mortgage or rent
 Minimum credit card payments
 Car loan
 Student loans
 Alimony/child support payments
 Other loans or lines of credit
Example:
Let's assume Sam has the following debt expenses:
 Mortgage = $950
 Minimum credit card payments = $235
 Car loan = $355
So, $950 + $235 + $355 = $1,540 total monthly debt payments
You don't need to include payments you make for car insurance, utilities, health insurance, groceries and other monthly expenses that don't involve financing. As a general guideline, if it doesn't show on your credit report, it's not factored into your debttoincome ratio by lenders.

02Total Your Monthly Income
The next step to determining your debttoincome ratio is calculating your monthly income.
Start by totaling your monthly income. Add up the amount you receive each month from:
 Gross income from a W2 job or selfemployment
 Bonuses or overtime
 Alimony/child support
 Other income from various sources
Example
Remember, Sam spends $1,540 each month on debt payments. Each month, he receives income as follows:
 monthly gross income = $3,500
 child support = $500
Sam's total monthly income = $3,500 + $500 = $4,000.
Note: Multiply a weekly income by 4 and bimonthly income by 2 to calculate your total monthly income. Or, if you know your annual salary, divide by 12 to get to your monthly income.

03Doing the Simple Math
Once you've calculated what you spend each month on debt payments and what you receive each month in income, you have the numbers you need to calculate your debttoincome ratio. To calculate the ratio, divide your monthly debt payments by your monthly income. Then, multiply the result by 100 to come up with a percent.
Example
In our example, Sam's monthly debt payments total $1,540 and his monthly income totals $4,000. So, divide $1,540 by $4,000 and then multiply by 100.
$1540 / $4000 = .385 X 100 = 38.5 percent
Sam has a debttoincome ratio of 38.5 percent. 
04What Your Debt to Income Ratio Means
Your final result will fall into one of these categories.
36 percent or less is the healthiest debt load for the majority of people. If your debttoincome ratio falls within this range, avoid incurring more debt to maintain a good ratio. You may have trouble getting approved for a mortgage with a ratio above this amount.
37 percent to 42 percent isn't a bad ratio to have, but it could be better. If your ratio falls in this range, you should start reducing your debts.
43 percent to 49 percent is a ratio that indicates likely financial trouble. You should start aggressively paying your debts to prevent an overloaded debt situation.
50 percent or more is an extremely dangerous ratio. This means that more than half of your income goes toward debt payments each month. You should be aggressively paying off your debts. Don't hesitate to seek professional help.
Example
In our example, Sam has a debttoincome ratio of 38.5 percent. While this isn't a bad ratio, it could become worse if Sam increases his monthly debt payments without increasing his income.
How to Calculate Your Debt to Income Ratio
Your debttoincome (DTI) ratio is the percentage of your monthly income that goes toward paying your debt. It's important not to confuse your debttoincome ratio with your credit utilization, which represents the amount of debt you have relative to your credit card and line of credit limits.
Many lenders, especially mortgage and auto lenders, use your debttoincome ratio to figure out the loan amount you can afford based on your current income and the amount you're already spending on debt.
For example, a mortgage lender will use your debttoincome ratio to figure out the mortgage payment you can handle after all your other monthly debts are paid.
You can easily calculate your debttoincome ratio to figure out the percentage of your income that goes towards paying down your debts each month.