How Much House Can I Afford?

"How much house can I afford?" is one of the most important financial questions you will ever ask. Get it right, and you build wealth steadily while living comfortably. Get it wrong, and you join the roughly 30% of homeowners who describe themselves as "house poor" -- spending so much on housing that everything else suffers.

This guide walks through the proven frameworks lenders and financial advisors actually use, including the 28/36 rule and debt-to-income ratios. We will also cover the hidden costs that catch first-time buyers off guard and show you exactly how to calculate your personal affordability number.

The 28/36 Rule: Your Starting Point

The 28/36 rule is the gold standard that most conventional mortgage lenders use. It has two parts:

• The 28% rule (front-end ratio): Your total monthly housing costs -- mortgage principal, interest, property taxes, and homeowners insurance (PITI) -- should not exceed 28% of your gross monthly income.
• The 36% rule (back-end ratio): Your total monthly debt payments -- housing costs plus car loans, student loans, credit cards, and other debts -- should not exceed 36% of your gross monthly income.

Example: If your household earns $90,000 per year ($7,500/month gross), the 28% rule says your maximum monthly housing payment should be $2,100. The 36% rule says your total monthly debt load should stay under $2,700. If you have a $400 car payment and $200 in student loans, that leaves $2,100 for housing -- which happens to match the front-end limit.

But what if your existing debts are higher? Suppose you have $900/month in existing debt payments. The 36% rule caps your total at $2,700, leaving only $1,800 for housing -- less than the 28% front-end limit. In that case, the back-end ratio is the binding constraint.

You can check both ratios instantly with our debt-to-income ratio calculator.

Understanding Debt-to-Income (DTI) Ratios

Your debt-to-income ratio is the single most important number in mortgage qualification. It tells lenders what percentage of your gross income goes toward debt payments each month.

Here is how different DTI levels are generally viewed by lenders:

Note that the maximum DTI for a qualified mortgage (QM) under federal regulations is 43%. Some government-backed loans (FHA, VA) may allow up to 50% with strong compensating factors like excellent credit or significant cash reserves.

How Your Down Payment Affects Affordability

Your down payment has an outsized impact on what you can afford. A larger down payment means a smaller loan, lower monthly payments, and often a better interest rate. Here is how different down payment amounts affect a $350,000 home purchase:

The jump from 3% to 20% down on a $350,000 home saves nearly $400/month in principal and interest alone -- and eliminates PMI (private mortgage insurance), which typically costs 0.5% to 1% of the loan annually. On a $339,500 loan, PMI could add another $140 to $280 per month. Use our down payment calculator to see how different amounts affect your specific situation.

Hidden Costs Most Buyers Forget

Your mortgage payment is just part of the cost of owning a home. Here are the expenses that catch buyers off guard:

• Property taxes: Typically 0.5% to 2.5% of the home's assessed value per year. On a $350,000 home, that is $1,750 to $8,750 annually, or $146 to $729 per month.
• Homeowners insurance: Average is about $1,500 to $3,000 per year, depending on location, coverage level, and the home itself.
• HOA fees: If applicable, these run $200 to $500+ per month in many communities. They cover shared amenities and common area maintenance.
• Maintenance and repairs: Budget 1% to 2% of the home's value per year. For a $350,000 home, that is $3,500 to $7,000 annually. A new roof alone can cost $8,000 to $15,000.
• Utilities: Owning a home typically means higher utility bills than renting, especially for larger properties. Budget $200 to $400/month.
• Closing costs: A one-time expense of 2% to 5% of the purchase price. On a $350,000 home, expect $7,000 to $17,500 at closing.

When you add it all up, the true monthly cost of homeownership is typically 30% to 50% more than the mortgage payment alone. This is why financial advisors often recommend targeting a home price that is 3 to 4.5 times your annual gross income -- not the maximum a lender will approve.

What Lenders Will Approve vs. What You Can Comfortably Afford

There is a critical difference between what a lender says you qualify for and what you can actually afford. Lenders look at your gross income, not your take-home pay. They do not account for retirement contributions, childcare costs, grocery bills, or the fact that you like to take a vacation once a year.

A useful reality check: Calculate 25% of your take-home (after-tax) pay. If your housing payment exceeds that number, you may feel financially stretched. Many financial advisors consider this a more conservative and livable benchmark than the lender's 28% of gross.

For a household earning $90,000 gross, take-home might be around $5,800/month after taxes and deductions. Twenty-five percent of that is $1,450 -- significantly less than the $2,100 the 28% gross-income rule permits. This gap explains why many homeowners who "qualified" for their mortgage still feel financially stressed.

How Interest Rates Affect Your Buying Power

Interest rates have a dramatic effect on how much home you can buy at a given monthly payment. Here is what a $2,000/month principal-and-interest payment buys at different rates:

Every 1% increase in mortgage rates reduces your buying power by roughly 10%. Use our mortgage calculator to see exactly how different rates affect your monthly payment and total interest paid over the life of the loan.

Step-by-Step: Calculate Your Affordability

Here is a practical approach to finding your personal affordability number:

1. Find your gross monthly income. Add up all household income before taxes. If your household earns $100,000/year, that is $8,333/month.
2. Apply the 28% front-end ratio. Multiply gross monthly income by 0.28. Result: $2,333/month maximum for housing.
3. Calculate your back-end limit. Multiply gross monthly income by 0.36 ($3,000), then subtract existing monthly debts. If debts total $600/month, your back-end housing limit is $2,400.
4. Take the lower number. In this example, $2,333 (front-end) is the binding constraint.
5. Subtract estimated taxes, insurance, and PMI. A reasonable estimate is $500 to $800/month for a mid-priced home. Remaining for P&I: roughly $1,533 to $1,833.
6. Convert to a home price. At 7% on a 30-year mortgage, $1,700/month in P&I supports about a $255,500 loan, which with 20% down means a home price around $319,000.

Rather than doing all this math by hand, use our house affordability calculator to get a precise, personalized result that factors in your specific tax rate, insurance costs, and down payment.

Tips for Improving Your Affordability

If the numbers are not where you want them, here are practical strategies:

• Pay down existing debt. Every $300/month in debt you eliminate increases your housing budget by $300/month (potentially $45,000+ in buying power).
• Increase your down payment. Saving an extra $20,000 reduces your loan amount directly and may eliminate PMI.
• Improve your credit score. The difference between a 680 and 760 credit score can mean 0.5% to 1% lower interest rates -- potentially $50,000+ in lifetime savings.
• Consider a 15-year mortgage. Lower rates (typically 0.5% to 0.75% less) and faster equity building, but higher monthly payments.
• Look at different areas. Property taxes vary enormously by location -- from 0.3% in Hawaii to over 2% in New Jersey and Illinois.

Common Mistakes to Avoid

• Maxing out your approval. Just because a lender approves you for $400,000 does not mean you should spend $400,000. Leave breathing room.
• Ignoring future expenses. Planning to start a family? Expecting childcare costs of $1,000 to $2,000/month? Factor that in now.
• Draining your savings for the down payment. Keep at least 3 to 6 months of expenses in reserve after closing. Homes break down, and you need a financial cushion.
• Forgetting about move-in costs. New furniture, window treatments, minor repairs, and appliances can easily add $5,000 to $15,000.