The real test: your debt-to-income ratio and down payment

You can afford a house when three things line up: you have a down payment saved, your monthly debt payments plus the new mortgage stay below 43% of your gross monthly income, and you have money left over for property taxes, insurance, and maintenance. Most lenders won't go above that 43% threshold, and for good reason—it's the point where a single missed paycheck or emergency starts breaking your budget.

Start with your gross monthly income (what you earn before taxes). Multiply it by 0.43. That's your maximum monthly debt load, including the new mortgage payment. If you earn $5,000 a month gross, your limit is $2,150. Subtract what you already owe each month—car loans, student loans, credit cards, personal loans—and what's left is what you can spend on a mortgage, property taxes, homeowners insurance, and mortgage insurance if your down payment is under 20%.

The down payment itself matters because it determines whether you'll pay mortgage insurance (PMI) on top of your loan. A 20% down payment avoids PMI entirely. Anything less than 20% triggers it—usually 0.5% to 1% of your loan amount per year, added to your monthly payment. A $300,000 house with 10% down ($30,000) means a $270,000 loan, and PMI could add $100 to $150 to your monthly payment.

Key Takeaways

  • Your total monthly debt payments (including the new mortgage) should not exceed 43% of your gross monthly income, which is the standard lenders use to decide whether to approve you.
  • A 20% down payment eliminates mortgage insurance; anything less triggers PMI, which adds $100 to $300+ per month depending on the loan size.
  • Use an online mortgage calculator to see what monthly payment a given house price creates, then add property taxes, insurance, and HOA fees to get your true monthly cost.
  • Emergency savings of 3 to 6 months of expenses separate people who can afford a house from people who can afford a house until the first repair bill arrives.
  • The price you can borrow is not the price you can afford—lenders approve loans based on income, not on whether you'll sleep at night paying them.

Calculate what you can actually borrow

Use a mortgage calculator (available free from Bankrate, NerdWallet, or your bank's website) to see what monthly payment a given loan amount creates. The calculator asks for loan amount, interest rate, and loan term (usually 30 years). It will show you the principal and interest payment, but you must add property taxes, homeowners insurance, and PMI yourself—the calculator often doesn't include them.

Property taxes and insurance vary wildly by location. A $400,000 house in one county might have $300 monthly taxes and $150 insurance; the same house in another state could be $600 and $250. Call your county assessor's office or a local real estate agent and ask what the annual property tax rate is (usually expressed as a percentage of home value). Homeowners insurance quotes come from insurance companies directly—get three quotes before you assume a number.

Add those three costs (mortgage payment, property taxes, insurance) together. That's your housing payment. Now add your other monthly debts. If the total exceeds 43% of your gross income, the house is too expensive, even if a lender says yes. Lenders approve loans based on income ratios, not on whether you can actually live on what's left.

Account for the costs lenders don't include in your payment

A mortgage payment covers principal, interest, and (if applicable) PMI. It does not cover maintenance, repairs, utilities, or HOA fees. Homeowners typically spend 1% to 2% of the home's value per year on maintenance and repairs—a $300,000 house means $250 to $500 per month set aside for a new roof, water heater, foundation work, or plumbing. If you're buying a house built before 1980, add another 0.5% for potential lead paint remediation or older system upgrades.

If the house is in a planned community or condo, add the HOA fee to your monthly housing cost. HOA fees range from $100 to $500+ per month depending on what's included. They're separate from your mortgage payment and are often overlooked until after closing.

Utilities (electric, gas, water, sewer, trash) typically run $150 to $300 per month depending on climate and house size. A mortgage calculator won't include this, but it's real money that comes out of your budget every month.

Build a down payment without derailing your emergency fund

The standard advice—save 20% down—is correct for avoiding PMI, but it's not the only path. FHA loans require 3.5% down, conventional loans with PMI start at 3% down, and some first-time buyer programs go as low as 0% down. The trade-off is that lower down payments mean higher monthly payments because of PMI, and you're borrowing more money overall.

Before you commit to a down payment amount, make sure you have 3 to 6 months of living expenses in a separate savings account that won't be touched for the down payment. This is your true emergency fund—separate from the down payment fund. If you drain your emergency savings to buy a house, the first major repair or job loss will force you into debt or foreclosure.

A realistic timeline: save your emergency fund first (3 to 6 months of expenses), then save your down payment on top of that. If you earn $5,000 a month and your expenses are $3,500, your emergency fund should be $10,500 to $21,000. Only after that's solid should you start saving for down payment. If that timeline feels too long, the house is probably too expensive for your current income.

Test your budget before you commit

Once you know what your monthly mortgage, taxes, insurance, and utilities will be, live on that reduced budget for three months before you make an offer. If you're planning a $1,800 mortgage payment, set aside $1,800 per month in a separate account and don't touch it. Pay your other bills from what's left. If you can't do this for three months without stress or overdrafts, you can't afford the house.

This test catches two things: whether your actual spending leaves room for the payment, and whether the payment itself feels sustainable. A number on a calculator and a number you actually live with are different things. If the test fails, either save longer for a bigger down payment (which lowers the monthly payment) or look at less expensive houses.

Know when to say no to a lender's approval

A mortgage lender will approve you for more than you should borrow. Lenders use the 43% debt-to-income ratio because it's the legal maximum they can offer, not because it's comfortable. Many people who get approved at 43% end up house-poor—they can make the payment, but they can't save, they can't handle emergencies, and they can't enjoy their life outside the mortgage.

A safer target is 28% of gross income on housing costs alone (mortgage, taxes, insurance, HOA, utilities). At $5,000 gross monthly income, that's $1,400 for all housing. This leaves room for other debt, savings, and actual living. It's more conservative than what lenders will approve, but it's also the difference between affording a house and affording a house while still building wealth.

If a lender approves you for $500,000 but your 28% target is $350,000, trust your number. The lender is paid to lend; you're the one who has to live with the payment.

Frequently Asked Questions

What if I have student loans or credit card debt—does that disqualify me?

No, but it reduces how much house you can afford. Lenders count all monthly debt payments toward your 43% limit. If you owe $300 a month on student loans and $200 on credit cards, that's $500 already committed. On a $5,000 gross income, you have $2,150 available for all debt; $500 is already gone, leaving $1,650 for a mortgage payment. Pay down high-interest debt before house hunting if possible.

Can I afford a house if I'm self-employed?

Yes, but lenders require more documentation. Most want two years of tax returns, profit-and-loss statements, and bank statements to verify income. Some lenders average your income over two years, which can lower your approved amount if your business is growing. Start gathering these documents early and talk to a mortgage lender about their specific requirements before you start house hunting.

What if I have a co-signer—does that change what I can afford?

A co-signer's income and debts both count toward the 43% limit. If you earn $3,000 and your co-signer earns $2,000, your combined gross is $5,000, and your combined debts all count. This can increase your approved amount, but it also means the co-signer is legally responsible for the loan if you can't pay. Don't use a co-signer to stretch beyond what you can afford alone.

Should I get pre-approved before I start looking?

Pre-approval shows sellers you're serious and gives you a real number to work with, but it's not a binding commitment. A lender will verify your income, debts, and credit score and tell you a maximum loan amount. Use that number as a ceiling, not a target. Many people get pre-approved and then buy at the maximum, which is usually a mistake.

What if I can't save a 20% down payment—is PMI worth it?

PMI is worth it if you can't wait years to save 20% and you're in a market where prices are rising faster than you can save. A 10% down payment with PMI might cost you $150 more per month than 20% down, but if home prices rise 5% per year, you're building equity faster than you'd save by waiting. Run the numbers: compare the cost of PMI over five years against the cost of renting and saving longer.