When most people think about qualifying for a mortgage, they immediately think about one thing: their credit score.

While your credit score is certainly important, it isn’t the only number lenders look at. In fact, I’ve seen buyers with excellent credit qualify for less than they expected, while others with average credit qualified with no issues.

The difference often comes down to one number that many people have never even heard of until they apply for a loan.

It’s called your debt to income ratio, or DTI.

Understanding how it works before you begin shopping can save you time, frustration, and possibly even thousands of dollars.

What Is Debt to Income Ratio?

Your debt to income ratio compares your monthly debt obligations to your gross monthly income before taxes.

In simple terms, lenders want to know:

“After paying your current monthly obligations, do you have enough income left to comfortably handle a mortgage payment?”

A lower DTI generally indicates less financial strain, while a higher DTI means a larger portion of your income is already committed to existing debt.

How Is DTI Calculated?

The calculation is actually pretty simple.

Take your total monthly debt payments and divide them by your gross monthly income.

For example:

Monthly gross income:
$8,000

Monthly debts:

Car payment: $550

Student loan: $250

Credit card minimums: $150

Personal loan: $200

Total monthly debt:
$1,150

$1,150 ÷ $8,000 = 14.4% DTI

Now let’s add a proposed mortgage payment of $2,800.

Total monthly obligations become:

$3,950

$3,950 ÷ $8,000 = 49.4% DTI

That percentage plays a major role in determining whether you qualify.

What Debts Count?

Lenders typically include:

• Car loans

• Student loans

• Credit card minimum monthly payments

• Personal loans

• Installment loans

• Child support

• Alimony

• Existing mortgage payments

• Home equity loans

• Timeshare payments

• The new proposed housing payment, including principal, interest, taxes, insurance, mortgage insurance (if applicable), and HOA dues

What usually doesn’t count:

• Utility bills

• Cell phone bills

• Internet service

• Streaming subscriptions

• Car insurance

• Groceries

• Gasoline

• Medical insurance premiums deducted from payroll

Why DTI Matters More Than Most People Realize

Many buyers assume that because they have a high income, qualifying will be easy.

Not necessarily.

Here’s an example.

Buyer A earns $180,000 per year.

They have:

• Two car loans

• Student loans

• Several credit cards with balances

• A personal loan

Buyer B earns $110,000 per year.

They have:

• One modest car payment

• Very little credit card debt

Buyer B may actually qualify for more purchasing power because their monthly obligations are much lower.

Income is only half the equation.

Monthly debt matters just as much.

Every Loan Program Has Different Guidelines

There isn’t one magic DTI number that applies to every mortgage.

It depends on the loan program, your credit profile, reserves, down payment, and other compensating factors.

In general:

Conventional loans often allow debt to income ratios up to approximately 49.99%.

FHA loans can sometimes approve ratios around 50%, depending on the overall loan profile.

VA loans don’t have one fixed maximum DTI, but they evaluate your residual income along with your overall financial picture.

This is one reason online mortgage calculators can be misleading. They simply don’t know all the factors that go into an actual underwriting decision.

Small Changes Can Increase Buying Power

One of the best parts about reviewing your finances before shopping is that small improvements can sometimes make a surprisingly large difference.

For example:

Pay off a credit card with a $75 monthly payment.

Wait one month until your car loan is paid off.

Reduce revolving credit card balances.

Avoid financing furniture before closing.

Hold off on opening a new credit account.

I’ve seen situations where paying off one small monthly obligation increased someone’s purchasing power by $25,000 to $50,000.

That’s a pretty good return on a relatively small change.

Self Employed? It Gets More Complicated

If you’re self employed, own a business, receive commissions, bonuses, overtime, retirement income, or rental income, your qualifying income may not match what’s deposited into your bank account.

Lenders have specific guidelines for calculating income, and tax returns often tell a very different story than someone’s gross receipts.

That’s why it’s especially important for self employed borrowers to speak with a mortgage professional early in the process.

Common Mistakes Buyers Make

The weeks before closing are not the time to make major financial changes.

Some common mistakes include:

Buying a new vehicle

Financing furniture

Opening new credit cards

Making large unexplained bank deposits

Closing long established credit accounts

Co-signing for someone else’s loan

Even if you’ve already been pre-approved, these changes can affect your loan approval.

What You Can Do Before Applying

If you’re planning to buy a home in the next year, here’s a simple checklist.

✓ Pay every bill on time.

✓ Keep credit card balances low.

✓ Avoid taking on new debt.

✓ Continue saving for your down payment and reserves.

✓ Gather your financial documents early.

✓ Talk with a mortgage professional before you begin house hunting.

The Bottom Line

Your credit score may get all the attention, but your debt to income ratio often has just as much impact on your mortgage approval.

Knowing where you stand before you start shopping gives you options. Sometimes the solution isn’t earning more money. It’s making a few strategic adjustments that improve your financial picture.

If you’re thinking about buying a home, I’d be happy to review your numbers with you. Whether you’re ready now or planning for next year, understanding your options today can help you make better decisions when the time comes.