What is the 28/36 rule for mortgage affordability?

The 28/36 rule says you should spend no more than 28% of your gross monthly income on total housing costs (principal, interest, taxes, insurance, and HOA) and no more than 36% on all debt payments combined (housing plus credit cards, auto loans, student loans, etc.). Lenders use these ratios to gauge whether you can afford a mortgage.

How much house can I afford on a $75,000 salary?

On $75,000/year ($6,250/month gross), the 28% front-end limit caps your housing payment at $1,750/month. With 20% down and current rates, that typically supports a home price around $250,000–$275,000, depending on property taxes, insurance, and HOA. Use a mortgage affordability calculator to model your exact numbers.

Does my debt-to-income ratio affect how much mortgage I qualify for?

Yes. Your back-end DTI (all monthly debts divided by gross monthly income) directly limits your borrowing power. Most qualified mortgages cap DTI at 43%, but lenders prefer 36% or lower. Higher DTI means a lower maximum loan amount and a higher interest rate offer.

How much down payment do I need to buy a house?

Conventional loans require as little as 3% down, FHA loans 3.5%, and VA/USDA loans 0%. However, putting less than 20% down means paying private mortgage insurance (PMI), which adds $50–$300/month. A larger down payment lowers your payment, eliminates PMI, and reduces the loan amount.

Can I afford more house if I have no other debt?

Possibly. If your back-end DTI is well under 36% because you carry no car, student, or credit card debt, some lenders allow the front-end ratio to stretch to 33–35%. But stretching increases risk — keep a cash reserve so a single income disruption does not become a foreclosure.

How Much House Can I Afford? The 28/36 Rule Explained

Asking "how much house can I afford?" is the single most important financial question you will face before buying a home. The answer is not what a real estate listing will tell you, and it is rarely what a pre-approval letter shows either. It is a function of your gross monthly income, existing debt, down payment, and the full carrying cost of homeownership — principal, interest, property taxes, insurance, and HOA dues. Lenders distill all of this into two numbers called the 28/36 rule. Understand those ratios and you will never overpay for a house, even when a lender says you "qualify" for more.

A mortgage calculator gives you the monthly payment, but affordability is the gating decision that comes first. Below we break down the 28/36 rule, front-end and back-end debt-to-income (DTI) ratios, how your down payment and property taxes shift the math, and a full worked example on a $75,000 income. If you want to compare live offers, LendingTree lets you collect quotes from multiple lenders in one place.

What Is the 28/36 Rule?

The 28/36 rule is the rule of thumb lenders use to set a ceiling on how much housing debt you can carry relative to your income. The two numbers refer to two debt-to-income ratios:

28% front-end ratio — your total monthly housing payment (PITIA: principal + interest + property taxes + homeowners insurance + HOA, if any) should be no more than 28% of your gross monthly income.
36% back-end ratio — your total monthly debt obligations (housing payment plus credit card minimums, auto loans, student loans, child support, and any other recurring debt) should be no more than 36% of your gross monthly income.

These are guidelines, not hard laws. Conventional loans can be approved at back-end DTIs up to 43% (sometimes 50% for strong borrowers), and some government-backed programs are more flexible. But 28/36 is where prudent affordability lives. The Consumer Financial Protection Bureau (CFPB) recommends using these thresholds as a self-test before you ever talk to a loan officer, because lenders will qualify you based on their risk tolerance — not your real-world budget for groceries, childcare, and retirement savings.

Front-End DTI: The Housing Ratio

The front-end ratio isolates housing costs. To calculate it, divide your expected monthly housing payment by your gross monthly income:

Front-end DTI = (PITIA) ÷ (gross monthly income) × 100

If you earn $75,000/year, your gross monthly income is $6,250. At the 28% ceiling, your maximum housing payment is $1,750/month. That $1,750 has to cover all of the following:

Principal & interest — the loan payment itself
Property taxes — vary widely by location (0.3% in Hawaii to 2.5%+ in parts of New Jersey and Texas)
Homeowners insurance — typically $1,000–$3,000/year depending on coverage and region
HOA dues — if applicable, can add $50–$500+/month
Mortgage insurance (PMI) — required if you put less than 20% down on a conventional loan

Notice that the principal-and-interest portion of the $1,750 is only what is left after taxes, insurance, and HOA. This is why the same income buys very different house prices in different zip codes. Use the mortgage calculator to test scenarios with your local property tax rate and insurance quotes.

Back-End DTI: The Total Debt Ratio

The back-end ratio is the lender's true pass/fail test. It includes your front-end housing payment plus every other recurring debt on your credit report:

Back-end DTI = (housing payment + all other monthly debt) ÷ (gross monthly income) × 100

On $6,250 monthly gross income, the 36% back-end ceiling caps your total debt payments at $2,250/month. If your housing payment is $1,750, that leaves only $500 for auto loans, student loans, and credit card minimums combined. A $400 car payment plus a $150 student loan payment leaves nothing for credit cards — and disqualifies you from the loan you "front-end-qualify" for.

What counts in back-end DTI?

Mortgage payment (PITIA)
Minimum credit card payments
Auto loan and lease payments
Student loan payments (lenders may use 1% of the loan balance if on deferment)
Child support and alimony
Personal loan payments
Any co-signed debt

DTI Quick-Reference Table

The table below shows the 28% and 36% ceilings across common income levels:

Gross Annual Income	Gross Monthly Income	Max Housing Payment (28%)	Max Total Debt Payment (36%)
$50,000	$4,167	$1,167	$1,500
$75,000	$6,250	$1,750	$2,250
$100,000	$8,333	$2,333	$3,000
$125,000	$10,417	$2,917	$3,750
$150,000	$12,500	$3,500	$4,500

These ceilings assume no other debt. In reality every dollar of auto or student loan payment shrinks the housing budget below the 28% figure, which is why most borrowers realistically buy at a front-end ratio closer to 22–26%.

How Your Down Payment Changes Affordability

Down payment affects affordability in three distinct ways: the loan amount, the interest rate offer, and whether you pay mortgage insurance.

3%–5% down (conventional 97 / HomeReady / Home Possible): Lowest barrier to entry but requires PMI and you will pay interest on a larger balance. Max loan = home price minus down payment.
3.5% down (FHA): Federal Housing Administration loan. Requires mortgage insurance premium (MIP), often for the life of the loan.
10% down: Lower PMI than 3% down, and you finance less. Good middle ground.
20% down: Eliminates private mortgage insurance entirely on conventional loans. Often unlocks the best rate tier. Total interest paid is lower because the loan is smaller.

A common mistake: assuming a bigger down payment always raises affordability. It lowers your payment, but tying up $100,000 in home equity can deplete your emergency fund and raise your risk if income drops. The CFPB recommends keeping 3–6 months of expenses in liquid reserves even after closing.

Property Taxes, Insurance, and HOA: The Hidden Costs

Principal and interest dominate lenders' marketing, but property taxes and insurance can easily add $300–$700/month and are required parts of your PITIA payment. They vary dramatically by location:

Property tax — 0.3% of home value/year (Hawaii) up to 2.4%+ (parts of NJ, IL, TX). On a $300,000 house that ranges from $75/month to $600/month.
Homeowners insurance — Average $1,500–$2,500/year nationally, but coastal and wildfire-prone areas can hit $4,000+.
HOA / condo fees — $50 to $1,000+/month. Condos and planned communities bundle amenities, landscaping, and external maintenance. HOA dues count toward your front-end ratio.
PMI — Typically 0.3%–1.5% of the loan balance per year until you reach 20% equity. On a $250,000 loan that is $62–$313/month.

These expenses are why a $300,000 home in Texas with high taxes may carry the same monthly payment as a $360,000 home in a low-tax state. Always model taxes and insurance in your affordability math — the mortgage calculator includes fields for both.

Worked Example: $75,000 Income

Let's put the 28/36 rule to work on a $75,000 salary. Assume the borrower carries a $300 car payment and a $150 student loan payment, contributes 5% down, and lives in a state with average property taxes (1.1%) and insurance ($1,800/year).

Step 1 — Gross monthly income

$75,000 ÷ 12 = $6,250/month

Step 2 — Apply the back-end 36% cap

Max total monthly debt = $6,250 × 0.36 = $2,250

Subtract existing debt: $2,250 − $300 (car) − $150 (student loan) = $1,800 max housing payment

Step 3 — Subtract taxes, insurance, PMI

On a hypothetical $275,000 home with 5% down ($13,750), the loan is $261,250. Property tax at 1.1% ≈ $252/month. Insurance ≈ $150/month. PMI on a 95% LTV conventional loan ≈ $160/month. That is $562/month in non-P&I housing costs.

Available for principal & interest = $1,800 − $562 = $1,238/month

Step 4 — Solve for loan size

At a 7% interest rate on a 30-year fixed mortgage, a $1,238 P&I payment supports roughly a $186,400 loan. Adding back the $13,750 down payment yields an affordable home price of roughly $200,000 — far below the $275,000 the front-end ratio suggested in isolation.

This is the gap everyone underestimates. The back-end ratio is the binding constraint for most buyers with existing debt, and property taxes plus insurance quietly erase another $500+/month of borrowing power. Run the same calculation with your own income, debts, and local tax rate in the mortgage calculator.

How Lenders Decide How Much Mortgage You Qualify For

Qualification is not affordability — it is the lender's risk assessment layered onto the same ratios. A lender will pull a tri-merge credit report (FICO scores from all three bureaus), verify income with W-2s and pay stubs, and run automated underwriting (DU for Fannie Mae, LP for Freddie Mac, GUS for USDA). The resulting pre-approval tells you the maximum loan amount at which the lender will fund, given:

Credit score — 760+ unlocks the best rate tier; below 620 most conventional programs are unavailable.
DTI — Cap of 43% for qualified mortgages, but each product has its own overlay (Fannie Mae allows up to 50% with strong compensating factors).
Reserves — 2–6 months of PITIA in liquid assets for jumbo and investor loans.
Down payment source — Must be sourced and seasoned for 60 days; gift funds allowed with documentation.

Pre-approval amounts are almost always higher than the 28/36 rule would suggest, because lenders protect themselves with PMI and higher rates, not with your monthly budget. You can shop that pre-approval against other lenders in minutes. LendingTree aggregates offers from multiple lenders so you can compare rates, points, and fees side by side. Rocket Mortgage offers a fully online approval and fast closing if speed matters, and Better.com advertises no lender fees, which can save $1,000–$3,000 at closing.

Factors That Reduce How Much House You Can Afford

Watch for these affordability-killers that the formulas do not always flag:

New credit inquiries — A new auto loan right before applying shrinks your back-end DTI headroom and can drop your score 5–10 points.
Co-signed debt — Counts fully against your DTI even if someone else pays.
Adjustable-rate mortgages — Affordability at the teaser rate can disappear at the first reset.
Deferred student loans — Most programs now count 1% of the loan balance as the monthly payment even on deferment or IBR.
High utility / climate costs — Not part of DTI but a real monthly burden on a larger or older home.

How to Raise Your Affordability Before You Buy

Pay down consumer debt first. Every $100/month of cleared debt adds roughly $33,000 in mortgage borrowing power at a 7% rate.
Increase your down payment. Bigger equity means lower PMI, lower rate, and a smaller loan — each of which raises affordability on its own.
Raise your credit score into the 740+ tier. A 60-point bump can shave 0.25–0.5% off your rate, lowering your payment and raising your max loan.
Shop more than one lender. Rates and fees vary by 0.5%+ between lenders. Even half a point on a $300,000 loan is $100/month.
Consider a lower-tax jurisdiction or newer construction if your target payment is constrained.

The Bottom Line

How much house you can afford is not the same as how much mortgage you qualify for, and the difference can be tens of thousands of dollars. The 28/36 rule gives you a hard ceiling rooted in your gross income: no more than 28% of monthly income to housing, no more than 36% to all debt. Once property taxes, insurance, and PMI eat into your payment, the loan size you can actually service shrinks fast. Run your own numbers with the mortgage calculator, hold yourself to a back-end DTI at or below 36%, and only buy a home whose total monthly cost leaves room for retirement contributions and an emergency fund. That is the difference between a homeowner and a house-poor borrower.