What Is Debt-to-Income Ratio and Why Does It Matter for a Mortgage?

The Basic Formula

For example, if your qualifying monthly debts total $2,600 and your gross monthly income is $7,000:

Your back-end DTI would be approximately 37%.

The CFPB uses this same basic calculation and notes that acceptable DTI limits vary by lender and loan product. Current agency and lender guidance changes over time, so verify the figures that apply today with your lender and the applicable source.

What Does "Gross Monthly Income" Mean?

Gross income is generally income before:

• Federal taxes
• State taxes
• Retirement contributions
• Health insurance deductions
• Other payroll deductions

But not every dollar deposited into your account necessarily counts as qualifying mortgage income.

A lender may need to verify that income is:

• Stable
• Documented
• Expected to continue
• Eligible under the chosen mortgage program

What Debt Counts in DTI?

Depending on the loan program and borrower, monthly payments considered in DTI can include:

• Proposed mortgage payment
• Property taxes
• Homeowners insurance
• Mortgage insurance
• HOA assessments
• Car loans
• Student loans
• Credit-card minimum payments
• Personal loans
• Other mortgages
• Certain alimony or child-support obligations
• Other recurring debts required by underwriting rules

What Usually Does NOT Count as Mortgage DTI Debt?

Ordinary living expenses generally are not counted in the technical DTI formula in the same way. Examples may include:

• Groceries
• Gas
• Cell phone
• Streaming services
• Utilities
• Entertainment

But that does NOT mean those expenses do not matter to your real-life budget.

A lender can approve a payment that technically fits underwriting while the borrower personally feels financially stretched because of other living expenses.

Front-End vs. Back-End DTI

Mortgage lenders may talk about two ratios.

Front-End Ratio

This compares the proposed housing expense with gross monthly income.

Depending on the program and calculation, the housing expense can include:

• Principal
• Interest
• Property taxes
• Insurance
• Mortgage insurance
• HOA

Back-End Ratio

This includes the housing expense PLUS other qualifying monthly debt obligations.

This is usually the more complete picture of the borrower's debt burden.

Example

Gross monthly income: $8,000

Proposed housing expense: $2,200

Car payment: $500

Student loan: $300

Credit-card minimums: $200

Front-End

Back-End

That buyer has a front-end housing ratio of about 27.5% and a total DTI of 40%.

What Is a "Good" DTI?

There is no single universal number.

As an educational guideline:

• A lower DTI generally gives the borrower more flexibility.
• Around 36% total DTI has historically been viewed as a relatively conservative benchmark.
• Fannie Mae's current manual-underwriting guidance uses 36% as the standard maximum total DTI for manually underwritten loans, and allows up to 45% when specified credit and reserve requirements are met. Confirm the current manual-underwriting guidance with Fannie Mae and your lender before relying on it.
• VA uses 41% as an important guideline, but VA underwriting places significant emphasis on residual income and can approve certain borrowers above 41%.
• FHA and other loan programs may produce different results through automated underwriting and compensating factors.

Why Can Two Buyers With the Same DTI Get Different Results?

Because DTI is only part of underwriting.

Buyer A:

• 40% DTI
• Excellent credit
• Large reserves
• Stable employment
• Strong down payment

Buyer B:

• 40% DTI
• Recent late payments
• No reserves
• Unstable income

Same DTI. Very different loan file.

How Does DTI Affect How Much House You Can Buy?

Your existing debt consumes part of the monthly payment a lender can potentially approve.

That is why:

• A $700 car payment
• $400 student-loan obligation
• $300 credit-card minimums

can materially reduce home-buying power.

How Can You Lower DTI?

Possible strategies can include:

• Paying down qualifying debt
• Paying off a monthly obligation
• Increasing qualifying income
• Buying a lower-priced property
• Increasing down payment where useful
• Choosing a property with lower HOA
• Choosing a financing structure with a lower payment

But do NOT pay debt off blindly before asking the lender.

Sometimes using cash to eliminate debt helps qualification enormously. Other times, preserving that cash for down payment or reserves is more valuable.

Have the lender run the scenarios first.

How Lisa Helps

Lisa can use the buyer's actual approved payment range to shape the property search.

She can also help buyers compare homes where monthly ownership costs differ because of:

• HOA
• Special assessments
• Property taxes
• Insurance
• Assumable mortgage opportunities