The real limit is what your lender will approve, not what you want to spend

The most expensive home you can afford is the one a lender will finance while you can still pay your other bills. That sounds simple, but it depends on four things lenders actually measure: your income, your debts, the down payment you have saved, and current interest rates. A lender will typically approve you for a mortgage between 2.5 and 3 times your gross annual income, though some will go higher. If you make $60,000 a year, that usually means a loan of $150,000 to $180,000. But that is the lender's ceiling, not your personal limit—and there is a meaningful difference.

Your personal limit is lower. Lenders care whether you can make the payment; you need to care whether you can make the payment and still eat, save for emergencies, and handle a job loss. A mortgage that passes the lender's test can still wreck your budget. This guide walks you through how lenders think about affordability, what numbers they use, and how to figure out what actually works for your life.

Key Takeaways

  • Lenders use your debt-to-income ratio—the percentage of your gross monthly income that goes to all debts—to decide how much to lend, typically capping it at 43 percent.
  • Your down payment size directly affects the loan amount: a 20 percent down payment on a $300,000 home means borrowing $240,000, while a 3 percent down payment means borrowing $291,000.
  • The monthly payment includes not just the loan itself but property taxes, homeowners insurance, and mortgage insurance (if your down payment is under 20 percent), which can add hundreds of dollars to your actual cost.
  • Interest rates change the affordability math: a 1 percent difference in rate can change your monthly payment by $200 or more on a $300,000 loan.
  • A lender's approval does not mean you can comfortably afford the home—it means you meet their minimum standard, which leaves little room for emergencies or income changes.

How lenders calculate what you can borrow

Lenders use a formula called the debt-to-income ratio, or DTI. It is the percentage of your gross monthly income (before taxes) that goes toward debt payments. Lenders typically will not approve a mortgage that pushes your DTI above 43 percent, though some will go to 50 percent if you have a strong credit history and savings.

Here is how it works in practice. Say you make $5,000 gross per month. Forty-three percent of that is $2,150. That $2,150 has to cover your new mortgage payment plus every other debt you carry: car loans, student loans, credit cards, personal loans, anything with a monthly payment. If you already owe $400 a month on a car and $200 on student loans, you have $1,550 left for the mortgage. A lender will approve you for a loan that costs roughly $1,550 a month.

The catch: that $1,550 is not just the loan payment. It includes property taxes, homeowners insurance, and possibly mortgage insurance. In many states, property taxes alone eat 20 to 30 percent of that number. In high-tax areas, they can eat more. This means the actual loan payment—the part that goes to principal and interest—is often only $1,000 to $1,200 of that $1,550.

What your down payment actually controls

Your down payment is the cash you bring to the table. The rest is borrowed. If you buy a $300,000 home with a $60,000 down payment (20 percent), you borrow $240,000. If you put down $9,000 (3 percent), you borrow $291,000. The larger your down payment, the smaller your loan, and the smaller your monthly payment.

Down payment size also determines whether you pay mortgage insurance. If you put down less than 20 percent, the lender requires you to buy private mortgage insurance, or PMI. This is an insurance policy that protects the lender if you stop paying. It costs between 0.5 and 1.5 percent of the loan amount per year, added to your monthly payment. On a $291,000 loan, that can be $120 to $360 a month. Once you have paid down the loan to 80 percent of the home's original value, you can request to have PMI removed.

This means a smaller down payment does not just mean a bigger loan—it means a bigger monthly payment plus an extra insurance cost. The difference between putting 3 percent down and 20 percent down on a $300,000 home can be $300 to $400 a month.

Interest rates change the price you can afford

Interest rates fluctuate based on the broader economy. When rates are low, the same loan costs less per month. When rates are high, it costs more. A 1 percent difference in interest rate changes your monthly payment by roughly $200 on a $300,000 loan.

This matters because it changes what you can afford right now. If you were approved for a $300,000 home when rates were 3 percent, you might only be approved for a $250,000 home if rates jump to 5 percent—even though your income and debts have not changed. Conversely, if rates drop, the same income qualifies you for a larger loan.

You cannot control interest rates, but you can control when you shop for a mortgage. Getting pre-approved by a lender locks in a rate for a set period (usually 30 to 45 days). If you are serious about buying, getting pre-approved tells you the actual number you can borrow at today's rates, not a theoretical number.

The difference between what lenders approve and what you can afford

A lender's approval is a floor, not a ceiling. It answers the question: "What is the maximum we will lend you?" It does not answer: "What can you safely spend without damaging your finances?"

Lenders approve based on whether you can make the payment. They do not know your actual expenses—whether you have kids in expensive schools, aging parents you help support, or a car that is about to need $5,000 in repairs. They do not account for the fact that your income might drop, your job might change, or an emergency might drain your savings. They do not care whether you have money left over after the mortgage for groceries and gas.

A safer rule of thumb: aim for a mortgage payment that is no more than 25 to 28 percent of your gross monthly income, not 43 percent. If you make $5,000 a month, that means a mortgage payment of $1,250 to $1,400, not $2,150. This leaves room for property taxes, insurance, and the other debts you carry, while still preserving money for emergencies and life.

How to calculate your own affordability number

Start with your gross monthly income—the number before taxes. Multiply it by 0.28. That is a reasonable target for your total housing payment (mortgage, taxes, insurance, and mortgage insurance if applicable).

Next, estimate your property taxes and insurance. Property tax rates vary wildly by state and county—from under 0.5 percent of home value per year in Hawaii to over 2 percent in New Jersey. Insurance varies by location and home age, but typically runs $1,000 to $2,000 per year. Ask a local real estate agent or insurance agent for estimates in the area where you want to buy.

Subtract those estimated costs from your housing budget. What is left is available for the loan payment itself. Use an online mortgage calculator (search "mortgage payment calculator") to see what loan amount produces that monthly payment at current interest rates. That loan amount, plus your down payment, is the home price you can afford.

Example: You make $6,000 gross per month. Twenty-eight percent is $1,680. Property taxes in your area run about $250 a month on a $300,000 home, and insurance is $150 a month. That leaves $1,680 − $250 − $150 = $1,280 for the loan payment. At a 6 percent interest rate, $1,280 a month buys you roughly a $213,000 loan. If you have $50,000 saved for a down payment, you can afford a $263,000 home.

What happens if you stretch beyond what you can afford

Buying more house than your budget allows creates predictable problems. Your mortgage payment crowds out other expenses. You skip maintenance because you have no money left. A job loss or income cut becomes a crisis instead of an inconvenience. You cannot save for emergencies or retirement. You become trapped—you cannot sell without losing money, and you cannot afford to stay.

Lenders will approve you for more than you should borrow because their job is to lend, not to protect your financial security. That approval is not a signal that you should spend that much. It is a signal that you have hit their risk threshold, not yours.

Frequently Asked Questions

Can I get approved for more than the lender's standard 43 percent debt-to-income ratio?

Some lenders will approve up to 50 percent DTI if you have a credit score above 740, significant savings, and a stable income history. But higher approval does not mean higher affordability for your life. The 43 percent standard exists because loans above that ratio have higher default rates.

Does my credit score affect how much I can borrow?

Your credit score affects the interest rate you get, not the loan amount itself. A higher score gets you a lower rate, which means a lower monthly payment on the same loan. A lower score gets you a higher rate and a higher monthly payment. Over 30 years, a 1 percent difference in rate costs tens of thousands of dollars.

What if I have a co-signer or spouse with income?

Lenders add both incomes together and both debts together to calculate DTI. If you and a spouse make $8,000 combined and have $500 in other debts, you can afford a higher mortgage payment than if you were applying alone. But both of you are equally responsible for the loan, so both incomes need to be stable.

How much should I actually put down?

Twenty percent eliminates mortgage insurance and is the traditional target. But 10 to 15 percent is reasonable if it means you keep more emergency savings. Anything under 5 percent means paying mortgage insurance for years, which adds significant cost. Never put down so much that you have less than three to six months of expenses in savings after closing.

What if interest rates drop after I get approved?

You can refinance—take out a new loan at the lower rate to pay off the old one. Refinancing costs money in closing costs, so it only makes sense if the rate drop is at least 0.5 to 1 percent and you plan to stay in the home long enough to recoup those costs.