What Is DTI and Why Does It Matter for Your Mortgage?

Credit score gets most of the attention when people talk about mortgage approval — but lenders care just as much about a number called DTI. Here's what it is, how yours is calculated, and what to do if you want to improve it before you apply.

DTI = Debt-to-Income Ratio

It's exactly what it sounds like: the percentage of your gross monthly income that goes toward debt payments. Lenders use it to understand whether you have enough income — after all your existing obligations — to reliably take on a mortgage payment.

How to Calculate Yours

Add up all your monthly debt payments:

• Minimum credit card payments
• Car loan payment
• Student loan payment
• Any other recurring loan payments
• Your projected new mortgage payment (principal + interest + taxes + insurance)

Divide that total by your gross monthly income (before taxes). Multiply by 100. That's your DTI percentage.

What's Considered a Good DTI?

• Under 36%: Strong position. Most lenders are comfortable here and you'll have access to the best rates.
• 36–43%: Acceptable for most loan types, though you may face more scrutiny or slightly higher rates.
• 43–50%: Some lenders will work with you here, but your options narrow considerably.
• Above 50%: Most conventional lenders will decline. FHA loans have some flexibility up to around 57% in certain situations, but it's tight.

Front-End vs. Back-End DTI

There are actually two DTI numbers lenders look at — and it's worth knowing the difference:

• Front-end DTI: Just your housing costs (mortgage + taxes + insurance) divided by gross income. Lenders generally want this under 28%.
• Back-end DTI: All debts including housing, divided by gross income. This is the more commonly referenced number — most lenders want it under 43%.

The House Money calculator uses the 28% front-end rule to calculate the salary any listing requires. That's the industry standard for "comfortably affordable."

How to Improve Your DTI Before You Apply

DTI is one of the most actionable numbers in home buying because you can actually move it — sometimes quickly.

• Pay down revolving debt first. Credit card balances have the most immediate impact on your DTI because the minimum payments are relatively high compared to the balance.
• Pay off installment loans if you have the cash. Eliminating a car payment completely removes it from your DTI calculation.
• Don't take on any new debt in the months before applying. No new car loan, no new credit card, no financing anything. Every new payment increases your DTI.
• Consider documented side income. Additional income that's consistent and can be verified can help your DTI ratio significantly.
• Look at a lower purchase price. A smaller loan = a smaller mortgage payment = a lower front-end DTI. Sometimes the numbers just work better with a different home.