What You Can Actually Afford vs. What a Lender Will Approve

A lender will approve you for far more than you should actually borrow. Banks use a formula called the debt-to-income ratio — they look at your gross monthly income and allow your total monthly debt payments (mortgage, car loans, credit cards, student loans) to reach 43% to 50% of that income. That is their risk tolerance, not yours.

What you can afford depends on three separate numbers: how much you have saved for a down payment, what your actual monthly expenses are (not just debt), and how much house payment would leave you with a real emergency fund and room to live. A lender's approval is a ceiling, not a recommendation.

Start by calculating your gross monthly income — that is your salary before taxes. Then list every monthly debt payment you already have: car loans, student loans, credit cards, personal loans. Add them up. Multiply your gross income by 0.43. That is the maximum total debt payment a lender will typically allow, including a new mortgage. Subtract your existing debts from that number. What remains is the mortgage payment a lender would approve.

Key Takeaways

  • Lenders approve based on a debt-to-income ratio of 43% to 50%, but that does not mean you should borrow that much.
  • Your actual affordability depends on your down payment, your existing expenses, and how much monthly cash you need to stay stable.
  • A common rule of thumb is that your housing payment should not exceed 28% of your gross monthly income, though your situation may differ.
  • The mortgage payment itself is only part of the cost — you also pay property taxes, homeowners insurance, and possibly HOA fees and mortgage insurance.
  • Use an online mortgage calculator to see how different down payments and interest rates change your monthly payment.

The 28% Rule and Why It Matters

Many financial advisors suggest keeping your housing payment to no more than 28% of your gross monthly income. This is narrower than what lenders allow, and it exists for a reason: it leaves room for everything else.

If you earn $5,000 gross per month, 28% is $1,400. That $1,400 covers your mortgage principal and interest, but it does not cover property taxes, homeowners insurance, HOA fees, or mortgage insurance (if you put down less than 20%). Those costs can easily add another $300 to $600 per month depending on your location and the home price. So your actual housing cost might be $1,700 to $2,000, which is 34% to 40% of your income — still reasonable, but noticeably higher than the 28% figure suggests.

The 28% rule is a starting point, not a law. If you have no other debt, a large emergency fund, and stable income, you might comfortably go higher. If you have student loans, a car payment, or irregular income, you should stay well below it.

What Costs Beyond the Mortgage Payment You Need to Budget

The mortgage payment itself — the number a lender quotes — covers only the principal and interest. It does not include the other costs that come with owning a home, and lenders know this. That is why they use the 43% debt-to-income ratio instead of 28%: they are accounting for the fact that housing costs are broader than just the loan payment.

Property taxes vary wildly by location. In some states they run 0.3% of the home value per year; in others they run 1.5% or higher. A $300,000 home in a high-tax area might cost $400 to $500 per month in property taxes alone. Your lender will estimate this and include it in the total housing cost they quote you.

Homeowners insurance is required by any lender. It typically costs $100 to $200 per month for a standard home, though it varies by location, the home's age, and your coverage choices. Homes in flood zones or areas prone to hurricanes cost significantly more to insure.

Mortgage insurance (called PMI, or private mortgage insurance) is required if you put down less than 20%. It typically costs 0.5% to 1% of the loan amount per year, paid monthly. On a $250,000 loan, that is $100 to $200 per month. You can remove it once you have paid the loan down to 80% of the home's value, but that takes years.

HOA fees explore only if you buy a condo or a home in a planned community. They can range from $100 to $500 or more per month and cover common area maintenance, sometimes including trash, water, or insurance. Check the HOA's financial statements and reserve fund before you buy — a poorly managed HOA can raise fees sharply.

How Your Down Payment Affects What You Can Afford

The larger your down payment, the smaller your monthly payment. This is straightforward math, but it also affects whether you pay mortgage insurance.

If you put down 20% or more, you avoid PMI entirely. If you put down 10%, you pay PMI for the life of the loan (or until you refinance). If you put down 5%, PMI is higher and lasts longer. On a $300,000 home, the difference between a 5% down payment and a 20% down payment can be $200 to $300 per month in PMI alone, plus a higher principal balance means a higher base payment.

Saving for a larger down payment takes time, but it directly lowers your monthly cost and reduces the total interest you pay over the life of the loan. If you are not ready to put down 20%, that is normal — many first-time buyers put down 5% to 10% — but you should understand that your monthly payment will be higher than someone who put down more.

Some programs offer down payment help through nonprofits, employers, or state housing agencies, though these vary by location and income. Your mortgage lender can point you toward programs in your area.

Using a Mortgage Calculator to Test Different Scenarios

An online mortgage calculator lets you see how changes in price, down payment, interest rate, and loan term affect your monthly payment. You enter the home price, down payment amount, interest rate, and loan term (usually 15 or 30 years), and the calculator shows you the principal and interest payment. Many also include fields for property taxes, insurance, and HOA fees so you can see the full monthly cost.

Run several scenarios. See what happens if you buy a $300,000 home versus a $350,000 home. See what happens if interest rates move up 0.5%. See what happens if you put down 10% instead of 15%. This is not a commitment — it is information. The goal is to find the price range where your monthly payment feels sustainable given your other expenses and your emergency fund.

Remember that the interest rate you see in a calculator is an estimate. Your actual rate depends on your credit score, your down payment, the loan type, and current market rates. A mortgage lender can give you a more precise rate after they review your finances.

Stress-Testing Your Budget: What If Rates Go Up or Your Income Changes

Interest rates change. Your income might change. Your expenses might change. Before you commit to a house payment, think about what happens if one of these shifts.

If you are getting an adjustable-rate mortgage (ARM), your payment will increase after the fixed period ends. If you are locking in a fixed rate now, your payment stays the same, but you should still think about whether you could handle a higher payment if you had to refinance in five years at a higher rate.

If your income is variable — you work on commission, you are self-employed, or you have a seasonal job — use a conservative estimate of your income, not your best year. Lenders typically average your income over two years for self-employed borrowers, and they want to see stability.

If you have a job offer that starts after closing, or if you are counting on a bonus or a raise, be cautious. Lenders base approval on income you have already earned and documented. Promised future income usually does not count.

Red Flags: When a House Payment Is Too High

A house payment is too high if it leaves you with no emergency fund, no room for unexpected repairs, or no ability to save. Homes have costs beyond the payment: a roof lasts 20 to 30 years, a water heater lasts 10 to 15 years, HVAC systems fail, plumbing breaks. If your payment is so large that you cannot set aside $200 to $300 per month for these eventual costs, you have overextended.

A payment is also too high if it forces you to carry high-interest debt. If buying a house means you cannot pay down credit cards or you have to take out a personal loan for a car, the house is too expensive right now. Debt at 6% (a mortgage) is cheaper than debt at 20% (a credit card), so prioritize the lower-cost debt.

Another red flag: if the payment requires both partners in a household to work, and one job is unstable or might change. Life happens. A job loss, a health issue, or a family emergency can happen to anyone. Your housing payment should be sustainable on one income if you have a partner, or with a reasonable buffer if you are single.

Frequently Asked Questions

What if I have student loans or a car payment? Does that reduce how much house I can afford?

Yes. Lenders add all your monthly debt payments together when they calculate your debt-to-income ratio. If you owe $400 per month on student loans and $350 on a car, that is $750 that counts against your housing budget. Paying down these debts before you buy a house increases your approved mortgage amount and your actual affordability.

Can I afford a house if I have not saved 20% for a down payment?

Yes. Most first-time buyers put down 5% to 10%. You will pay mortgage insurance, which increases your monthly cost, but you can still buy. The trade-off is a higher payment now and more total interest over the life of the loan. As you build equity, you can refinance or pay extra principal to remove the insurance faster.

How much should I have in savings after I buy the house?

Aim for three to six months of expenses in an emergency fund, separate from your down payment. After closing, you should still have cash available for home repairs, job loss, or other emergencies. If buying a house drains your savings completely, you are buying too much house.

What is the difference between a 15-year and a 30-year mortgage?

A 15-year mortgage has a higher monthly payment but you pay far less interest overall and own the home sooner. A 30-year mortgage has a lower monthly payment but costs significantly more in total interest. Most buyers choose 30 years because the lower payment is easier to fit into a budget, but if you can afford 15 years, you save money long-term.

Should I get pre-approved before I start looking at houses?

Yes. Pre-approval tells you the price range where you can actually borrow, and it shows sellers you are a serious buyer. Pre-approval is not a commitment — it is a lender's estimate of what they would lend based on your current finances. Your actual approval comes later, after you have made an offer and the lender orders an appraisal.