Start with your gross monthly income, then subtract what you already owe
The amount of house payment you can afford depends on two numbers: how much money comes in each month, and how much already goes out to other debts. Most lenders use a debt-to-income ratio — they want your total monthly debt payments (mortgage, car loans, credit cards, student loans, everything) to stay below 43% of your gross monthly income. Some lenders will go to 50%, but that leaves little room for emergencies.
Start by calculating your gross monthly income — that is what you earn before taxes. If you make $60,000 a year, your gross monthly income is $5,000. At a 43% ratio, your total debt payments should not exceed $2,150 per month. If you already pay $400 on a car loan and $150 on student loans, that leaves $1,600 for a mortgage payment.
The mortgage payment itself includes four things: principal (the loan amount you are paying down), interest, property taxes, and homeowners insurance. Lenders call this PITI. Some lenders also require you to pay mortgage insurance if you put down less than 20%, which adds to the monthly cost. Your actual payment will be higher than just the principal and interest.
Key Takeaways
- Most lenders cap your total monthly debt payments at 43% of your gross income, though some allow up to 50%.
- Your mortgage payment includes principal, interest, property taxes, insurance, and possibly mortgage insurance — not just the loan amount.
- A larger down payment (20% or more) lowers your monthly payment and removes the mortgage insurance requirement.
- Your credit score, savings for closing costs, and employment history affect how much a lender will actually offer you, not just the math.
How your down payment changes what you can afford
The size of your down payment directly affects your monthly payment. If you are buying a $300,000 house and put down 20% ($60,000), you borrow $240,000. If you put down only 5% ($15,000), you borrow $285,000. That extra $45,000 in borrowing adds roughly $240 to $300 to your monthly payment, depending on the interest rate and loan term.
Putting down less than 20% also triggers private mortgage insurance (PMI), which protects the lender if you stop paying. PMI typically costs 0.5% to 1.5% of the loan amount per year, added to your monthly payment. On a $285,000 loan, that could be $120 to $360 per month. You can remove PMI once you have paid down the loan to 80% of the home's value, but that takes years.
A larger down payment means you borrow less, pay less interest over time, avoid PMI, and lower your monthly payment — all of which means you can afford a more expensive house or have more breathing room in your budget.
Interest rates and loan terms shift your payment up or down
The interest rate you receive depends on market conditions, your credit score, and the loan term (usually 15, 20, or 30 years). A 30-year loan has a lower monthly payment than a 15-year loan on the same amount, but you pay far more interest over time. A 15-year loan costs more per month but you own the house faster and pay less total interest.
Interest rate changes hit your payment hard. On a $240,000 loan over 30 years, the difference between a 6% rate and a 7% rate is roughly $160 per month. That same rate difference on a 15-year loan is about $240 per month. Your credit score, down payment size, and loan type (conventional, FHA, VA, USDA) all affect the rate you are offered.
Before you commit to a price range, get a pre-qualification or pre-approval from a lender. Pre-qualification is a rough estimate based on what you tell them. Pre-approval involves a credit check and verification of income and assets — it shows sellers you are serious and gives you a real number to work with.
Property taxes and insurance add hundreds to your monthly cost
Your mortgage payment is not just principal and interest. Property taxes vary wildly by location — a $300,000 house in one county might have annual property taxes of $3,000, while the same house in another state could be $8,000 or more. That is $250 to $667 per month built into your payment.
Homeowners insurance is required by lenders and covers damage to the structure and your belongings. Costs vary by location, age of the house, and what you are insuring, but expect $1,000 to $2,000 per year ($85 to $167 per month) in most places. Older homes, homes in flood zones, or homes in areas with high crime or weather risk cost more.
When a lender quotes you a monthly payment, ask whether it includes taxes and insurance. Some quotes show only principal and interest, which makes the payment look smaller than it actually is. The full PITI payment is what you will actually owe each month.
What happens if you stretch beyond the 43% rule
Some lenders will approve you for a mortgage that exceeds the 43% debt-to-income ratio, especially if you have a large down payment, excellent credit, or stable income. But approval does not mean affordability. If your total debt payments are 50% or more of your gross income, a single setback — a job loss, medical emergency, or car repair — can make the payment impossible.
Lenders approve based on your ability to repay at the time of application. They do not account for future job changes, health issues, or rising property taxes. You are the one who has to live with the payment every month. A house you can technically afford is not the same as a house you can comfortably afford.
Many people who default on mortgages were approved for amounts that left no margin for error. The safest approach is to stay well below the 43% threshold — aim for 30% to 35% if you can — so you have room to handle unexpected costs.
Use the numbers to find your actual price range
Here is a concrete example. You earn $72,000 per year (gross monthly income: $6,000). You owe $300 on a car loan and $200 on student loans. Your total existing debt is $500 per month. At 43%, your total debt payments can be $2,580. That leaves $2,080 for a mortgage payment.
On a 30-year loan at 6.5% interest with no PMI, a $2,080 payment covers roughly $320,000 in borrowing. If you put down 20% ($80,000), you can afford a house around $400,000. If you put down only 5% ($20,000), you can afford roughly $320,000, and PMI will eat another $150 to $200 of that $2,080 payment, leaving less for principal and interest.
These numbers change with interest rates, property taxes in your area, insurance costs, and your credit score. Use an online mortgage calculator to plug in your actual numbers — your income, existing debts, down payment, and the current interest rate in your area. The result is a realistic range, not a may provide.
Frequently Asked Questions
What is the difference between pre-qualification and pre-approval?
Pre-qualification is an estimate based on information you provide — no verification required. Pre-approval involves a credit check and proof of income and assets. Pre-approval carries more weight with sellers and gives you a more accurate number for what you can borrow.
Can I afford a house if I have bad credit?
Yes, but you will pay a higher interest rate, which raises your monthly payment. FHA loans allow credit scores as low as 500 to 580, but rates are higher than conventional loans. A lower credit score can add $200 to $400 per month to your payment on the same house.
Should I use a 15-year or 30-year loan?
A 30-year loan has a lower monthly payment, which matters if you are tight on cash. A 15-year loan costs more per month but you pay roughly half the total interest and own the house faster. Choose based on what your budget can handle, not what sounds better.
What if my income varies month to month?
Lenders typically average your income over the past two years for self-employed people or those with variable pay. If your income is unstable, lenders may use a lower number or require more savings as a cushion. Have recent tax returns and pay stubs ready.
Does my spouse's income count if we are not married?
No. Only income in your name counts toward your debt-to-income ratio. If you are applying jointly with a spouse or partner, both incomes count, but both debts count too. Some couples apply separately to keep one person's debt off the application.