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Guide · 4-minute read

What Is Debt-to-Income Ratio (and Why It Decides Your Loan)?

It's the single number that quietly decides how much home you can buy. The good news: once you understand it, you can move it.

When a lender looks at your application, they're really asking one question: can you comfortably handle a new mortgage payment on top of what you already owe? The number they use to answer that is your debt-to-income ratio, or DTI. It matters more than most buyers realize, and it's one of the few things you can actually improve before you apply.

What It Actually Measures

Your DTI compares the money going out every month for debt against the money coming in before taxes.

DTI = monthly debt payments ÷ gross monthly income

"Gross" means your income before taxes and deductions. If you earn $6,000 a month before taxes and your required debt payments add up to $2,250, your DTI is 37.5%. That's it. The lower the number, the more room you have for a mortgage.

The Two Numbers Lenders Look At

Front-End

Housing only

Just your future mortgage payment (principal, interest, taxes, and insurance) divided by your income.

Back-End

All your debt

Your mortgage plus every other monthly payment: car, student loans, credit cards, and more. This is the one that matters most.

Most loan programs care most about the back-end number, because it shows your whole picture.

A Real Example

Say you earn $6,000 a month before taxes, and you're looking at a mortgage payment of about $1,500.

How the math works

Car payment$400
Student loan$200
Credit card minimums$150
New mortgage payment$1,500
Back-end DTI37.5%

$2,250 in total monthly debt ÷ $6,000 income = 37.5%. Comfortably inside most lenders' guidelines.

What's a Good DTI?

There's no single magic cutoff, and it varies by loan program, but here's the general landscape:

What Counts (and What Doesn't)

This trips people up constantly. DTI only includes debt, not your everyday living expenses.

Counts toward DTI

  • Mortgage or rent (future payment)
  • Car loans and leases
  • Student loans
  • Credit card minimum payments
  • Personal and other loans
  • Child support or alimony

Does not count

  • Utilities and cell phone
  • Groceries and gas
  • Health insurance premiums
  • Streaming and subscriptions
  • Savings contributions
  • Day-to-day spending

How to Improve It Before You Apply

Because DTI is a ratio, you can move it from either side. A few of the fastest levers:

Pay down a balance. Knocking out a car loan or a credit card can drop your ratio noticeably overnight. Avoid new debt. Financing a car or furniture right before you apply can quietly push you over the line, so hold off until after closing. Add income. A documented raise, a side income, or a co-borrower all count. Adjust the target. A slightly lower purchase price lowers the mortgage payment, which lowers the ratio.

Don't know your DTI? Use our free calculator to find your number in under a minute.
Open the DTI calculator →

Not sure where your number lands?

Tell us your income and your monthly payments, and we'll run your real DTI in a few minutes, then show you exactly what it means for your price range.