Debt-to-Income Ratio Calculator

How a loan originator calculates DTI

A loan originator does not ask what you spend each month. They build the ratio from documents: your credit report supplies the debts, your pay stubs and tax returns supply the income, and the loan you are applying for supplies the housing payment. The steps are the same at almost every lender.

1. Work out qualifying income: gross monthly income that is documented, stable and likely to continue.
2. Work out the proposed housing payment for the new loan, not your current rent.
3. Add the minimum monthly payment on every debt that appears on your credit report, plus obligations that do not, such as child support.
4. Divide housing by income for the front-end ratio, and housing plus debts by income for the back-end ratio.
5. Compare both ratios with the limits of the loan program, usually through an automated underwriting system.

With the figures the calculator starts with: $6,500 of income, a $1,700 housing payment and $690 of other debt. The front-end ratio is 1,700 / 6,500 = 26.2%. The back-end ratio is 2,390 / 6,500 = 36.8%.

What counts as income

Lenders use gross income, before tax and deductions, and they only count what they can document.

Income that is new, irregular or undocumented is often left out entirely. A raise counts once it shows on a pay stub. Cash income that does not appear on a tax return does not count.

What goes into the housing payment

The housing figure is the full monthly cost of the new home, often written PITIA:

• principal and interest on the new mortgage;
• property taxes;
• homeowners insurance, and flood insurance where required;
• mortgage insurance: PMI on a conventional loan or the monthly premium on an FHA loan;
• homeowners association or condo dues;
• payments on any second mortgage or home equity line on the property.

Estimate that payment with the mortgage calculator, then enter the total here as your housing cost.

Which debts count, and which do not

A few details change the total more than people expect:

• Credit cards count at the minimum payment on the report, not at what you actually pay. A card you clear every month still counts at its minimum if a balance was reported.
• Student loans count even when they are deferred or in forbearance. If the credit report shows no payment, the lender assigns one, commonly 0.5% to 1% of the balance per month depending on the loan program.
• Installment loans with ten or fewer payments left can often be left out of the ratio.
• A debt paid by someone else, such as a car loan your parent pays, can usually be excluded with twelve months of proof that they make the payments.

DTI limits by loan type

There is no single cut-off. Each loan program sets its own guideline, and automated underwriting can approve higher ratios when the rest of the file is strong.

You will still see 43% described as the legal limit for a qualified mortgage. That was true until the rule changed: since 2022 the general qualified mortgage definition is based on the loan's pricing, and the lender must consider and verify DTI without a fixed 43% cap. Many lenders and programs still use 43% as their own line.

What the limits mean in dollars

For $6,500 of gross monthly income and $690 of other debt, here is the largest housing payment that fits under each back-end limit:

Paying off the $380 car loan in this example would raise every figure in the last column by $380, which at 6.5% over 30 years supports roughly $60,000 more borrowing.

What helps when the ratio is high

Underwriters call these compensating factors. They do not change the ratio, but they can make a higher one acceptable:

• a high credit score;
• cash reserves left after closing, measured in months of housing payments;
• a larger down payment;
• a new housing payment close to what you already pay in rent;
• a long, stable employment history;
• for VA loans, residual income above the required minimum.

Ways to lower your DTI before applying

• Pay off a small installment loan completely. Removing a whole payment helps more than reducing several balances a little.
• Pay credit cards down before the statement date, so a lower balance and minimum payment are reported.
• Avoid opening new credit or financing a car in the months before you apply.
• Add a co-borrower whose income counts, bearing in mind their debts count too.
• Choose a less expensive home or a larger down payment to reduce the proposed housing payment.

Guidelines are updated from time to time and individual lenders add their own rules, so treat these figures as a guide and confirm the details with a loan originator. To see the payment a given loan would create, use the mortgage calculator; to see the cash needed up front, use the down payment calculator.