How much house you can afford depends on your gross income, existing debts, down payment, credit score, and local property costs. A general rule: most buyers can comfortably afford a home priced at 3 to 4 times their annual gross income. On a $100,000 salary with 10% down and moderate debt, that means a home in the $300,000-$400,000 range — though lenders may approve you for significantly more. Every online affordability calculator gives you a single number and calls it a day. The problem is that number is usually wrong — or at least dangerously incomplete. As underwriting engineers, we have built the systems that actually determine how much a lender will let you borrow. The answer depends on two DTI ratios, six cost components most calculators ignore, and a gap between "qualification limit" and "comfortable payment" that can make or break your financial future.

How to Calculate Your Home Affordability: Step-by-Step

Before diving into the theory, here is the exact process for calculating how much house you can afford. Run these five steps with your own numbers:

1. Calculate your gross monthly income. Take your annual salary (before taxes) and divide by 12. If you have a co-borrower, add both incomes. Example: $100,000 annual = $8,333/month.
2. Set your front-end DTI ceiling. Multiply gross monthly income by 0.28 (conservative) or 0.33 (moderate). This is your maximum total monthly housing cost. Example: $8,333 × 0.28 = $2,333/month.
3. Subtract non-mortgage housing costs. Estimate monthly property taxes (home price × local tax rate ÷ 12), homeowners insurance (~$200/month), PMI if putting less than 20% down (loan amount × 0.007 ÷ 12), and any HOA dues. Subtract these from your Step 2 number. What remains is your maximum principal + interest payment.
4. Convert the P&I payment to a loan amount. Use the mortgage payment formula or any amortization calculator. At 6.8% for 30 years, every $1,000/month in P&I supports approximately $153,700 in loan balance.
5. Add your down payment to get your maximum home price. If you have $40,000 saved for a 10% down payment, your max home price = loan amount ÷ 0.90. Then cross-check against your back-end DTI: total debts (housing + car + student loans + credit cards) should stay below 36-40% of gross income for financial comfort.

2026 Housing Market Context: What You Are Up Against

Before running the affordability math, it helps to understand the current market environment — because the numbers look different than they did even two years ago.

• Median existing-home price: $398,400 as of early 2026 (National Association of Realtors), up from $389,800 in 2025. The median new-home price is $413,500 (U.S. Census Bureau).
• 30-year fixed mortgage rate: 6.8% average in March 2026 (Freddie Mac Primary Mortgage Market Survey), down from a peak of 7.79% in October 2023 but still double the 3.0% rates of early 2021.
• Housing affordability index: The NAR Housing Affordability Index sat at 93.2 in Q4 2025 — any reading below 100 means the median-income family cannot qualify for the median-priced home under standard underwriting. This is the worst sustained affordability stretch since the early 1980s.
• Median household income: Approximately $80,600 (Census Bureau 2025 estimate). At a 6.8% rate with 10% down, that income supports a comfortable home purchase of roughly $250,000-$280,000 — well below the median home price.

The bottom line: in 2026, the median American household is mathematically priced out of the median American home under conservative affordability standards. That is not a reason to overextend — it is a reason to understand these formulas precisely so you can find the price point that works for your specific situation.

The 28/36 Rule — and Why It Is Outdated

The 28/36 rule is a mortgage affordability guideline stating that homeowners should spend no more than 28% of gross monthly income on housing costs and no more than 36% on total debt payments. You have probably heard it repeated everywhere. This rule dates back to Fannie Mae underwriting guidelines from the 1990s and was designed for an era of 7-8% mortgage rates and median home prices of $120,000.

Here is why the rule no longer reflects reality in 2026:

• Fannie Mae and Freddie Mac now approve DTIs up to 50%. Their automated underwriting systems (Desktop Underwriter and Loan Product Advisor) routinely approve borrowers with back-end DTIs of 45-50% when compensating factors exist — strong reserves, excellent credit, or low loan-to-value ratios.
• FHA loans allow up to 57% back-end DTI with manual underwriting and strong compensating factors. The standard FHA threshold is 43%, but exceptions are common.
• The Qualified Mortgage (QM) safe harbor moved. The CFPB's 2021 rule change eliminated the hard 43% DTI cap for QM loans originated by GSE-eligible lenders. If Fannie or Freddie's automated systems approve it, it qualifies — regardless of DTI.

The 28/36 rule is a useful personal finance guideline, but it is not what lenders actually enforce. If you use 28/36 as your ceiling, you will underestimate your borrowing power. If you use the lender's actual ceiling (45-50%), you may overextend yourself. The real answer lives somewhere in between — and this guide will help you find it.

Front-End DTI vs. Back-End DTI: The Two Numbers That Decide Everything

Debt-to-income ratio (DTI) is the percentage of your gross monthly income that goes toward debt payments. Lenders calculate two separate DTI ratios when evaluating your mortgage application. Both must fall within acceptable ranges, and either one can kill your approval. For a deep dive into how DTI works across all loan types, see our complete debt-to-income ratio guide.

Front-End DTI (Housing Ratio)

This ratio isolates your housing burden. "Total Monthly Housing Costs" is not just your mortgage payment — it includes all six PITI+ components:

1. Principal — the portion of your payment reducing the loan balance
2. Interest — the cost of borrowing at your mortgage rate
3. Property taxes — typically 0.5%-2.5% of home value annually, depending on state
4. Homeowners insurance — averages $1,900-$2,400/year nationally in 2026
5. HOA dues — if applicable, ranges from $200-$800/month for condos
6. PMI (Private Mortgage Insurance) — required if your down payment is less than 20%, typically 0.5%-1.5% of loan amount annually

Most online calculators only account for principal and interest. They ignore property taxes, insurance, HOA, and PMI entirely — which is why their affordability estimates are inflated by 15-25%.

Back-End DTI (Total Debt Ratio)

"All Other Monthly Debt Payments" includes auto loans, student loans, credit card minimums, personal loans, child support, alimony, and co-signed loan obligations. It does not include utilities, groceries, subscriptions, or insurance premiums outside of your mortgage escrow.

Here is what lenders actually enforce in 2026:

Worked Examples: How Much House at $75K, $100K, and $150K Income

Let us run the actual math at three income levels. For all examples, we will use these 2026 baseline assumptions:

• Mortgage rate: 6.8% (30-year fixed, March 2026 average per Freddie Mac)
• Down payment: 10%
• Property tax rate: 1.2% of home value annually
• Homeowners insurance: $200/month
• PMI: 0.7% of loan amount annually (required with <20% down)
• HOA: $0 (single-family home)
• Existing monthly debts: $400 (car payment + credit card minimums)

Example 1: $75,000 Annual Income

Gross monthly income: $6,250

The front-end ratio is the binding constraint here at $1,750/month. Working backward from that housing payment:

• Subtract property taxes (~$280/month at 1.2% on ~$280K home), insurance ($200/month), and PMI (~$147/month)
• Remaining for principal + interest: $1,750 − $280 − $200 − $147 = $1,123/month
• At 6.8% for 30 years, $1,123/month supports a loan of approximately $172,000
• With 10% down, that is a home price of approximately $191,000

If the lender allows a 45% back-end DTI (Fannie Mae AUS approval), the math shifts:

• Back-end ceiling: $6,250 × 0.45 = $2,813 − $400 = $2,413/month for housing
• After taxes ($370), insurance ($200), PMI ($195): $1,648/month P&I
• Loan amount: ~$253,000 → home price: ~$281,000

Comfortable target at $75K income: $190,000-$220,000. The lender may approve you for $281,000, but at that price, over 45% of your gross income goes to debt — leaving dangerously thin margins for savings, maintenance, and emergencies.

Example 2: $100,000 Annual Income

Gross monthly income: $8,333

At the conservative 28% front-end ratio:

• After taxes (~$380), insurance ($200), PMI (~$195): $1,558/month P&I
• Loan amount: ~$239,000 → home price: ~$266,000

At the lender's 45% back-end ceiling:

• $8,333 × 0.45 = $3,750 − $400 = $3,350/month for housing
• After taxes (~$500), insurance ($200), PMI (~$260): $2,390/month P&I
• Loan amount: ~$367,000 → home price: ~$408,000

Comfortable target at $100K income: $280,000-$340,000. This keeps your total debt-to-income ratio in the 35-40% range, leaving room for retirement savings, an emergency fund, and the inevitable home repairs that cost $5,000-$15,000 per year on average.

Example 3: $150,000 Annual Income

Gross monthly income: $12,500

At the conservative 28% front-end ratio:

• After taxes (~$530), insurance ($200), PMI (~$275): $2,495/month P&I
• Loan amount: ~$383,000 → home price: ~$426,000

At the lender's 45% back-end ceiling:

• $12,500 × 0.45 = $5,625 − $400 = $5,225/month for housing
• After taxes (~$740), insurance ($200), PMI (~$385): $3,900/month P&I
• Loan amount: ~$599,000 → home price: ~$665,000

Comfortable target at $150K income: $420,000-$520,000. At this income level, the gap between what lenders approve ($665K) and what is financially comfortable ($520K) is nearly $150,000 — which illustrates why lender qualification limits should never be treated as a budget target.

What Lenders Include in Housing Costs: The Full PITI+ Breakdown

The single biggest mistake borrowers make is confusing their mortgage payment with their total housing cost. Lenders do not make this mistake. Here is exactly what goes into the housing cost number that determines your front-end DTI:

Notice that principal and interest account for only 74% of the total housing cost in this example. The remaining 26% — taxes, insurance, and PMI — is invisible to borrowers who only look at their mortgage payment. A borrower who thinks they can afford a $2,055/month payment actually needs to budget $2,789/month, a difference of $734 that can push them over the DTI threshold. To understand how lenders process all these components simultaneously during underwriting, read our explanation of how credit decisioning engines work.

The Gap Between "Can Qualify" and "Can Comfortably Afford"

This is the most important section of this guide, and the one that most affordability articles skip entirely.

The maximum amount a lender will approve you for is NOT the amount you should spend. Lender qualification limits are designed to manage the lender's default risk, not to ensure your financial wellbeing. A 43-50% back-end DTI means that nearly half of your gross income — and an even larger share of your net income after taxes — goes to debt payments.

Consider a borrower earning $100,000 gross ($8,333/month). At a 45% back-end DTI, they owe $3,750/month in total debt payments. But their take-home pay after federal and state taxes, Social Security, and Medicare is approximately $6,200-$6,800/month depending on state. That $3,750 in debt payments now consumes 55-60% of net income, not 45%.

What is left: $2,450-$3,050/month for everything else — groceries, utilities, transportation, childcare, healthcare, retirement savings, emergency fund, home maintenance, and discretionary spending. For a family of four, that is dangerously tight.

The "Comfortable Affordability" Framework

Based on analysis of default rates correlated with DTI levels, here is the framework we recommend:

Our recommendation: target the 28-33% front-end and 36-40% back-end range. This gives you borrowing power close to what lenders will approve while maintaining financial resilience. For complete context on how lenders evaluate your total debt picture, see our debt-to-income ratio guide.

How Your Credit Score Changes What You Can Afford

Your credit score does not just determine whether you get approved — it directly changes how much house you can afford by altering your interest rate and PMI cost. We have seen this in production underwriting systems: a 100-point credit score difference can shift buying power by $50,000-$95,000 on the same income.

A borrower with a 760+ FICO score can afford approximately $105,000 more house than a borrower with a 620 score — on the exact same income, down payment, and debt load. The rate differential (6.50% vs. 7.60%) accounts for roughly $60,000 of that gap, and the PMI differential (0.30% vs. 1.50%) accounts for the remaining $45,000. If your score is below 720, spending 3-6 months improving it before applying could be the single highest-ROI move in your homebuying process. For strategies on boosting your score, see our guide to soft pulls vs. hard pulls — understanding which credit actions affect your score and which do not is the first step.

How Loan Type Changes Your Buying Power

The loan program you choose shifts your affordability ceiling — sometimes dramatically. Each program has different DTI limits, down payment requirements, and insurance costs, all of which feed into how much house you can buy. Here is how the same $100,000-income borrower (10% down, $400/month existing debt, 700 FICO) fares under each major loan type:

VA loans offer the highest buying power for eligible borrowers because zero down payment and no monthly mortgage insurance eliminate two of the biggest drags on affordability. A $100K-income veteran can afford roughly $50,000 more home than the same borrower using a conventional loan. FHA loans provide a lower entry barrier (3.5% down, 580 minimum FICO) but carry lifetime mortgage insurance premiums that reduce long-term affordability. To understand how underwriting systems evaluate these trade-offs across loan programs, see our credit decisioning engine explainer.

Down Payment Impact on Buying Power

Your down payment affects affordability in three ways that compound on each other — and understanding all three is critical.

Effect 1: Lower Loan Amount = Lower Monthly Payment

This one is obvious. A larger down payment reduces the loan balance, which reduces the principal and interest portion of your monthly payment. On a $400,000 home at 6.8%:

Effect 2: PMI Elimination at 20%

With less than 20% down, lenders require private mortgage insurance. PMI rates in 2026 range from 0.5% to 1.5% of the loan amount annually, depending on your credit score and LTV ratio. On a $360,000 loan at 0.7% PMI, that is an extra $210/month added to your housing cost.

At 20% down, PMI disappears entirely — saving you $210/month in this example. Combined with the lower P&I payment, a 20% down payment reduces your total monthly housing cost by approximately $600/month compared to 5% down on the same home.

Effect 3: Higher Buying Power Through DTI Math

Because a larger down payment reduces your monthly housing cost, it also reduces your front-end DTI — which means lenders will approve you for a higher-priced home. A borrower earning $100,000 with 20% down and no PMI can qualify for a home priced roughly $50,000-$70,000 more than the same borrower with 5% down, because the PMI savings and lower P&I free up DTI capacity.

This creates a paradox: spending more on the down payment lets you buy a more expensive home while keeping the same monthly payment. For many borrowers, the path to a better home is not earning more income — it is saving a larger down payment. Understanding the full approval process, including how lenders verify assets for your down payment, is covered in our mortgage pre-approval guide.

Costs That Are Not in the DTI Calculation but Will Wreck Your Budget

Lenders calculate DTI based on debt obligations only. They do not account for the full cost of homeownership, which includes expenses that can add 20-40% on top of your mortgage payment:

• Home maintenance and repairs: Budget 1-2% of home value per year. On a $350,000 home, that is $3,500-$7,000 annually ($290-$583/month). A new roof costs $8,000-$15,000. An HVAC replacement runs $5,000-$12,000. These are not "if" expenses — they are "when."
• Utilities: $200-$500/month depending on home size, climate, and energy efficiency. Typically 40-80% more than renting the same square footage.
• Lawn and exterior maintenance: $100-$300/month for lawn care, pest control, gutter cleaning, and seasonal upkeep.
• Furnishing a larger space: First-time homebuyers spend an average of $10,000-$15,000 on furniture and appliances in the first year.
• Closing costs: 2-5% of the home price, paid at purchase. On a $350,000 home, expect $7,000-$17,500 in closing fees. For a complete breakdown, see our closing costs guide.

None of these appear in the DTI calculation. A lender who approves you at a 43% back-end DTI has not accounted for the $500/month in maintenance, utilities, and upkeep that will push your actual housing burden to 50%+ of gross income.

How Location Changes Affordability: Property Tax and Insurance by State

We used a flat 1.2% property tax rate in the examples above, but in reality, property tax rates vary by a factor of 7x across states — and that variation alone can shift your affordable home price by $40,000-$80,000.

A $350,000 home in New Jersey costs $597/month more in property taxes and insurance than the same-priced home in Hawaii. That $597 difference consumes DTI capacity that could otherwise support roughly $92,000 in additional mortgage — meaning a buyer who can afford a $350,000 home in Hawaii can only afford approximately $258,000 in New Jersey, all else equal. Insurance costs in catastrophe-prone states (Florida, Texas, Louisiana) have surged 30-60% since 2023, making this an increasingly important variable in the affordability calculation.

Cash Reserves: The Affordability Factor Most Buyers Overlook

Lenders do not just check whether you can make the monthly payment — many also verify that you have cash reserves after closing. Reserves are measured in months of housing payments (PITI) remaining in your bank and investment accounts after the down payment and closing costs are paid.

• Conventional loans: Typically require 2 months of reserves for primary residences, 6 months for second homes and investment properties.
• Jumbo loans: Often require 6-12 months of reserves. On a $4,000/month housing payment, that is $24,000-$48,000 that must remain in your accounts post-closing.
• FHA/VA/USDA: Generally no formal reserve requirements for primary residences, though reserves serve as a compensating factor for borderline DTI approvals.

Here is why this matters for affordability: if you have $80,000 in savings and need $40,000 for a 10% down payment plus $15,000 for closing costs, you have $25,000 remaining. If the lender requires 6 months of reserves at $2,800/month PITI, that is $16,800 — leaving only $8,200 for moving expenses, furnishing, and immediate repairs. Cash reserves effectively reduce your usable down payment, which in turn reduces your affordable home price. Budget for reserves before setting your price ceiling.

First-Time Buyer Programs That Expand Your Budget

If you are a first-time homebuyer (defined as someone who has not owned a home in the past three years), several programs can materially expand your buying power:

• Down payment assistance (DPA) programs: Available in all 50 states through state housing finance agencies. Most offer 3-5% of the purchase price as a forgivable grant or low-interest second mortgage. On a $300,000 home, that is $9,000-$15,000 you do not have to save — which means your existing savings stretch further toward reserves and closing costs.
• FHA loans with 3.5% down: The minimum down payment is $10,500 on a $300,000 home. Some DPA programs can cover the entire 3.5%, resulting in effectively zero out-of-pocket down payment.
• Conventional 3% down (HomeReady/Home Possible): Fannie Mae's HomeReady and Freddie Mac's Home Possible programs allow 3% down for borrowers earning at or below 80% of area median income. Income from boarders, non-borrower household members, and rental units can be counted.
• VA loans (0% down): No down payment required for eligible veterans — the single most powerful affordability tool in the mortgage market.
• Employer-assisted housing programs: An increasing number of employers (especially in healthcare, education, and tech) offer $5,000-$25,000 in homebuyer assistance as an employee benefit. Check with your HR department before assuming your down payment budget is fixed.

Combining a DPA grant with an FHA or HomeReady loan can reduce your required out-of-pocket cash by $15,000-$25,000, effectively letting you buy the same home with far less savings — or redirect those savings into a higher down payment that eliminates PMI and expands your DTI capacity. For the full pre-approval process including how to apply for these programs, see our mortgage pre-approval guide.

Quick Reference: Affordability by Income Level

Here is a summary table using 2026 assumptions (6.8% rate, 10% down, $400/month existing debts, 1.2% property tax, $200/month insurance):

These numbers shift significantly based on existing debt, down payment size, property tax rates, and PMI. A borrower earning $100,000 with $1,200/month in existing debts (car + student loans) sees their comfortable target drop from $320,000 to approximately $230,000. Debt reduction before buying is often the highest-ROI financial move a prospective homebuyer can make.

How to Increase Your Home Buying Power

If the numbers above are lower than you expected, here are the highest-impact levers — ranked by effectiveness:

1. Pay off existing debts before applying. Every $100/month in recurring debt you eliminate adds approximately $15,000-$20,000 to your home buying power at 2026 interest rates. Eliminating a $400/month car payment frees up $400 in DTI capacity, translating to roughly $60,000-$80,000 in additional buying power. A borrower who spends six months aggressively paying down debt before applying will almost always afford a better home than one who applies immediately. This is the single most effective strategy.
2. Increase your down payment to 20%. Eliminates PMI and increases your DTI capacity. Going from 10% to 20% down adds approximately $50,000-$70,000 in affordable home price.
3. Improve your credit score. A score above 740 gets you the best mortgage rates. The difference between a 680 and a 760 FICO score can mean 0.5-1.0% lower interest rate — which translates to $30,000-$60,000 in additional buying power on a 30-year mortgage. Start with the pre-approval process to understand where you stand; our pre-approval guide walks through each step.
4. Consider a 15-year mortgage only if you can afford the higher payment. The rate is typically 0.5-0.75% lower, but the monthly payment is 40-50% higher. This makes sense for high-income borrowers who want to build equity faster, not for those stretching to afford a home.
5. Add a co-borrower's income. A spouse or partner's income is included in the DTI calculation if they are on the mortgage application, directly increasing your borrowing capacity.

Frequently Asked Questions

The Bottom Line

How much house you can afford is not a single number — it is a range defined by your income, debts, credit score, down payment, loan type, and local costs. Lenders will approve you for more than you should spend. The formulas in this guide give you the tools to calculate both your maximum qualification limit and your financially comfortable target. Our recommendation: aim for the 28-33% front-end and 36-40% back-end DTI range, use the income-level summary table as your starting benchmark, and adjust for your specific credit score, location, and debt load. A home purchase that keeps you within these boundaries builds long-term wealth instead of long-term stress.