What you can afford depends on your income, debts, and down payment—not just the interest rate

A mortgage payment you can afford is one that leaves you money for everything else: property taxes, insurance, utilities, food, car payments, medical bills. Lenders use two numbers to decide how much they will lend you. The first is your debt-to-income ratio — the percentage of your gross monthly income that goes to all debt payments, including the new mortgage. The second is your housing ratio — the percentage of gross income that goes to housing costs alone (mortgage, property tax, homeowners insurance, and mortgage insurance if you put down less than 20 percent).

Most lenders cap the housing ratio at 28 percent and the debt-to-income ratio at 36 to 43 percent, depending on the loan type and your credit profile. But what a lender will approve and what you can actually afford without financial strain are different questions. A lender looks at whether you can make the payment. You need to look at whether making that payment leaves you with enough cushion for emergencies, savings, and the rest of your life.

Key Takeaways

  • Lenders typically allow housing costs up to 28 percent of your gross monthly income and total debt payments up to 36 to 43 percent, but these are ceilings, not recommendations for what is comfortable.
  • Your actual affordable payment depends on your other debts (car loans, student loans, credit cards), property taxes and insurance in your area, and how much emergency savings you have.
  • A down payment of less than 20 percent adds mortgage insurance to your monthly bill, which can add $100 to $500 per month depending on the loan size and your credit score.
  • The difference between what you can afford and what a lender will approve can be $300 to $800 per month — use your own budget, not the lender's formula, to set your limit.

How lenders calculate what they will approve

A lender starts with your gross monthly income — your salary before taxes. If you earn $60,000 per year, that is $5,000 per month gross. The lender then applies the 28 percent housing ratio: 28 percent of $5,000 is $1,400. That is the maximum they will allow for your mortgage payment, property tax, homeowners insurance, and mortgage insurance combined.

Next, the lender looks at your debt-to-income ratio. They add up every monthly debt payment you have: car loans, student loans, credit cards (they use the minimum payment, not your actual payment), personal loans, and the new mortgage. If your total debts cannot exceed 43 percent of gross income, and you earn $5,000 per month, your total debt payments cannot exceed $2,150. Subtract your existing debts from that number, and what remains is what the lender will allow for the mortgage payment.

These two numbers — the housing ratio and the debt-to-income ratio — are the guardrails. Whichever one is lower is your ceiling. A lender will not approve a mortgage that breaks either rule, regardless of the property value or your credit score.

The gap between what lenders approve and what you can afford

Lender approval formulas assume you have no other expenses. They do not account for groceries, utilities beyond the mortgage, childcare, transportation, medical costs, or savings. A 28 percent housing ratio leaves 72 percent of your income for everything else — but that 72 percent includes taxes, which take another 15 to 25 percent depending on your state and filing status. You are left with roughly 50 to 55 percent of gross income for all non-housing expenses.

For a household earning $5,000 per month gross, that is $2,500 to $2,750 for food, utilities, insurance, transportation, childcare, medical care, and savings combined. If you have a car payment of $400, student loans of $300, and credit card minimums of $100, you have already committed $800 of that $2,500 to debt. That leaves $1,700 for everything else — which is tight if you have children, live in a high-cost area, or have irregular expenses.

Financial advisors often recommend a lower ceiling: keeping your housing payment to no more than 25 to 30 percent of gross income, and keeping total debt payments to no more than 30 to 35 percent. This leaves more room for emergencies and savings. The difference between a 28 percent housing ratio and a 25 percent ratio is real money — on a $5,000 monthly income, it is $150 per month, or $1,800 per year.

How down payment size affects your affordable payment

A smaller down payment means a larger loan, which means a larger monthly payment. But it also means you pay mortgage insurance — a monthly fee that protects the lender if you default. If you put down less than 20 percent, you will pay private mortgage insurance (PMI) on a conventional loan, or mortgage insurance premium (MIP) on an FHA loan.

PMI typically costs 0.5 to 1.5 percent of the loan amount per year, paid monthly. On a $300,000 loan, that is $125 to $375 per month. The exact rate depends on your credit score, the loan-to-value ratio (how much you are borrowing relative to the home price), and the lender. FHA mortgage insurance is similar but has different rules: you pay an upfront premium (1.75 percent of the loan) and an annual premium (0.55 to 0.80 percent) for the life of the loan if you put down less than 10 percent.

This matters for affordability because mortgage insurance is part of your housing payment for the lender's ratio calculation. A $1,400 housing budget that includes $300 in mortgage insurance leaves only $1,100 for the actual mortgage payment, property tax, and homeowners insurance. Putting down 20 percent or more eliminates this cost and frees up that $300 for a larger mortgage payment.

Property taxes and insurance vary by location and change your real payment

Two homes with the same mortgage payment can have very different total housing costs depending on where they are. Property taxes range from less than 0.3 percent of home value per year in Hawaii and Louisiana to over 2 percent in New Jersey and Illinois. Homeowners insurance ranges from $600 to $2,000 per year depending on the state, the home's age, and your claims history.

A $300,000 home in New Jersey with a 2 percent property tax rate costs $6,000 per year in property tax alone — $500 per month. The same home in Hawaii costs $900 per year, or $75 per month. Homeowners insurance might add another $100 to $200 per month. These costs are not optional and are not part of the mortgage payment itself, but they are part of your housing payment for the lender's ratio calculation and part of your actual monthly expense.

Before you settle on an affordable payment, research the property tax rate and typical insurance costs in the area where you are looking. A mortgage payment that fits your budget in one state may not fit in another.

How to set your own affordable payment limit

Start with your gross monthly income. Subtract your existing monthly debt payments (car loans, student loans, credit cards, personal loans — use your actual payment, not the minimum). Subtract an estimate of property taxes and homeowners insurance for the area and price range you are considering. What remains is available for a mortgage payment and mortgage insurance.

From that number, subtract 10 to 15 percent as a buffer for expenses that are not captured in the lender's formula: higher utilities in winter, car repairs, medical costs, or a job loss. What is left is a reasonable mortgage payment ceiling for your situation.

Example: You earn $6,000 per month gross. Your car payment is $350 and student loans are $200. Property taxes and insurance in your target area run about $400 per month. You have $6,000 minus $350 minus $200 minus $400 = $5,050 remaining. A 15 percent buffer for unexpected costs is $758. That leaves $4,292 available for a mortgage payment. But you also need money for groceries, utilities, childcare, and savings — probably $2,000 to $2,500 per month. A realistic mortgage payment ceiling is $1,500 to $2,000, not the full $4,292.

This is more conservative than what a lender will approve, but it is also more honest about what leaves you with financial stability.

What happens if you stretch beyond what you can afford

A mortgage payment that is too high for your budget creates a cascade of problems. You skip or delay other payments — utilities, insurance, car loans — to make the mortgage. You stop saving for emergencies. When an unexpected cost arrives (a medical bill, a car repair, a job loss), you have no cushion. You then miss a mortgage payment, which damages your credit and can trigger foreclosure proceedings.

Lenders approve based on income and debt ratios, not on your actual spending patterns or life circumstances. A lender does not know if you have aging parents you help support, if your child has medical needs, or if your industry is unstable. You do. Use that knowledge to set a payment limit that is lower than what a lender will approve.

Frequently Asked Questions

What if I have no other debts — can I afford a higher mortgage payment?

Yes, but not as much higher as you might think. With no other debts, the housing ratio becomes your only constraint. A lender will allow up to 28 percent of gross income for housing. But you still need money for utilities, food, transportation, medical care, and savings. A 25 percent housing ratio is more realistic even with no other debts.

Does my credit score affect how much I can afford?

Your credit score affects the interest rate you pay and the mortgage insurance rate, which changes your monthly payment. A higher score gets a lower rate and lower insurance, reducing your payment by $50 to $200 per month. But it does not change the lender's debt-to-income or housing ratio limits — those are the same regardless of score.

Should I count my spouse's income if we are married?

Yes, if you are explore for the mortgage together. Lenders add both incomes and both debts. If you earn $4,000 and your spouse earns $3,000, your combined gross income is $7,000. Both of your debts count toward the debt-to-income ratio, so a car loan in your spouse's name reduces the mortgage amount you can both afford together.

What if the lender approves me for more than I think I can afford?

Lender approval is not a recommendation. It is the maximum they will lend based on income and debt ratios. You are not required to borrow the full amount. Set your own limit based on your budget and comfort level, and stick to it even if a lender says you can go higher.

Does the interest rate change how much I can afford?

The interest rate changes your monthly payment, which changes how much house price you can afford for a given payment. A lower rate means a lower payment for the same loan amount, or a larger loan for the same payment. But your affordable payment limit — based on your income and debts — does not change with the rate. You still cannot afford a payment that is 30 percent of your gross income just because the rate dropped.