Debt To Income Ratio Explained With Examples

Debt to income, usually shortened to DTI, is the share of your gross monthly income that goes to debt payments. Lenders use it to judge whether you can absorb a new payment, so the same ratio that keeps a car loan affordable can block a mortgage. The maths is simple, but which payments go into the top of the fraction is where most people get it wrong.

The Formula

DTI equals total monthly debt payments divided by gross monthly income, multiplied by 100. Gross means before tax and deductions, because lenders compare your obligations to your earning capacity rather than your take-home pay.

The numerator includes minimum credit card payments, car loans, student loans, personal loans, child support, alimony and the proposed new housing payment including property taxes, insurance and any association fees. The denominator is salary before tax plus regular bonuses, commission, benefit income and rental income that can be documented.

Excluded from the numerator: rent you are about to stop paying when you move, groceries, utilities, phone bills, insurance unrelated to the property, childcare and subscriptions. These affect affordability, but they are not debt payments under the standard definition.

Two Worked Examples

First example. Gross income 5,000 a month. Car loan 350, student loan 190, credit card minimums 150, proposed mortgage payment 1,400 all in. Payments total 2,090. Divide by 5,000 to get 0.418, or 41.8 percent. That sits above the 36 percent level many lenders like to see, so this borrower would likely be asked to reduce a balance or accept a smaller loan.

Second example. Gross income 7,500 a month. Car loan 300, card minimums 80, proposed mortgage 1,700 all in. Payments total 2,080. Divide by 7,500 to get 0.2773, or 27.7 percent. Same rough payment size, very different ratio, only because income is higher.

Lenders also look at the housing ratio on its own. Divide the proposed housing payment by gross monthly income. In the second example that is 1,700 divided by 7,500, which is 22.7 percent. A common guideline is to keep housing at or below 28 percent and total debt at or below 36 percent, though the limits vary by country, loan type and lender policy.

What Counts As Too High

Thresholds are guidelines rather than law. Many lenders treat 36 percent as a comfortable ceiling, 36 to 43 percent as a grey zone requiring compensating factors, and above 43 percent as likely to fail an automated approval.

Compensating factors include a large down payment, substantial savings after closing, a long steady employment record and low housing costs relative to income. A borrower at 40 percent with twelve months of reserves is treated very differently from one at 40 percent with nothing saved.

Credit cards distort the number in a way borrowers often miss. Lenders generally use the minimum payment, so a 6,000 balance at 2 percent adds 120 to the numerator. Paying that balance down to 2,000 drops the contribution to about 40, freeing 80 of monthly capacity without any change in income.

• Below 36 percent - Comfortable for most lenders, with room for the new payment.
• 36 to 43 percent - Possible approval, usually with compensating factors or a smaller loan.
• 43 to 50 percent - Difficult. Most mainstream approvals stop here without strong reserves.
• Above 50 percent - Debt payments consume more than half of gross income; focus on repayment first.

How To Improve Yours

Attack the numerator. Every pound or dollar of monthly payment you remove reduces DTI directly. Clearing a 150 card minimum on a 5,000 income cuts the ratio by 3 percentage points, which can change an approval decision.

Raising income helps the denominator but only if it is documented and predictable. Overtime and bonus income may be averaged or discounted, and self-employment income is usually assessed from tax returns, often over two years.

Run the calculation before applying. A declined application leaves a mark on your credit file, so check the ratio at two or three realistic loan sizes first. If you are close to a threshold, waiting one or two months of extra repayments can be worth more than applying immediately.

This article is educational only and is not financial advice. Figures vary by country and lender, so check the rules that apply where you live.