Mortgage Affordability: How Much Can You Borrow?

Quick answer

• Calculate your debt-to-income ratio (DTI) to estimate borrowing limits.
• Lenders generally prefer a DTI below 43%, but lower is better.
• Assess your down payment amount; a larger down payment reduces your loan amount and monthly payments.
• Factor in closing costs, which can add 2-5% of the loan value.
• Understand your credit score’s impact on interest rates and loan approval.
• Get pre-approved by a lender to get a realistic idea of your borrowing capacity.

Who this is for

• First-time homebuyers trying to understand their budget.
• Existing homeowners looking to refinance or purchase a new property.
• Individuals planning a major financial decision and wanting to gauge mortgage capacity.

What to check first (before you act)

Goal and timeline

Before diving into numbers, clarify what you want to achieve. Are you buying your first home, downsizing, or upgrading? Knowing your timeline helps prioritize actions. For example, if you aim to buy within six months, you’ll need to act faster on credit improvement and saving for a down payment than if you have a year or more.

Current cash flow

Understand exactly where your money is going each month. Track your income and all expenses, including discretionary spending. This will reveal how much surplus you have available for a mortgage payment, property taxes, insurance, and potential maintenance. A clear picture of your cash flow is crucial for realistic affordability.

Emergency fund or safety buffer

Ensure you have a solid emergency fund before taking on a mortgage. This fund should cover 3-6 months of essential living expenses. A mortgage payment is a significant, long-term commitment, and an emergency fund prevents you from defaulting if unexpected job loss or medical bills arise.

Debt and interest rates

List all your current debts, including credit cards, auto loans, student loans, and personal loans. Note the outstanding balance and the interest rate for each. High-interest debt can significantly impact your DTI and your ability to qualify for a mortgage, and it’s often wise to pay these down before borrowing more.

Credit impact

Your credit score is a major factor lenders use to determine your loan eligibility and interest rate. Check your credit reports for accuracy and understand your current score. Improving your credit score can lead to substantial savings over the life of a mortgage.

Step-by-step (simple workflow)

1. Assess your credit score

What to do: Obtain your credit reports from all three major bureaus (Equifax, Experian, TransUnion) and check your credit scores.
What “good” looks like: Scores in the high 700s or 800s generally qualify for the best interest rates. Scores above 620 are typically the minimum for mortgage approval, though rates will be higher.
A common mistake and how to avoid it: Assuming your score is good without checking. Avoid this by actively pulling your reports and scores from official sources.

2. Calculate your debt-to-income ratio (DTI)

What to do: Sum up your total monthly debt payments (student loans, car payments, credit card minimums, etc.) and divide by your gross monthly income.
What “good” looks like: Lenders often look for a front-end DTI (housing costs only) of 28% or less and a back-end DTI (all debts) of 36% or less. Many will go up to 43% for the back-end DTI, but lower is always more favorable.
A common mistake and how to avoid it: Forgetting to include all recurring debt payments, like alimony or child support. Avoid this by creating a comprehensive list of all financial obligations.

3. Determine your down payment

What to do: Decide how much cash you can realistically put towards a down payment.
What “good” looks like: A 20% down payment avoids private mortgage insurance (PMI) and reduces your loan amount. However, many loan programs allow for much lower down payments (e.g., 3.5% for FHA loans, 0% for VA or USDA loans for eligible borrowers).
A common mistake and how to avoid it: Depleting all savings for the down payment, leaving no funds for closing costs or emergencies. Avoid this by budgeting for both.

4. Estimate closing costs

What to do: Research typical closing costs in your area, which can include appraisal fees, title insurance, loan origination fees, and more.
What “good” looks like: Having 2-5% of the loan amount set aside for closing costs.
A common mistake and how to avoid it: Underestimating closing costs, which can be a significant surprise. Avoid this by asking lenders for a detailed Loan Estimate.

5. Calculate your maximum mortgage payment

What to do: Based on your DTI, down payment, and estimated closing costs, determine a comfortable monthly mortgage payment (principal, interest, taxes, and insurance – PITI).
What “good” looks like: A PITI payment that represents no more than 28-36% of your gross monthly income, leaving room for other expenses and savings.
A common mistake and how to avoid it: Focusing only on the principal and interest, forgetting property taxes and homeowner’s insurance. Avoid this by always including PITI in your calculations.

6. Use online affordability calculators

What to do: Utilize various online mortgage affordability calculators to get a preliminary estimate of how much you can borrow.
What “good” looks like: These tools provide a range based on your inputs, helping you set realistic expectations.
A common mistake and how to avoid it: Treating online calculator results as definitive loan approval. These are estimates, and a lender’s pre-approval is the true measure.

7. Get pre-approved for a mortgage

What to do: Apply for mortgage pre-approval with one or more lenders.
What “good” looks like: A pre-approval letter stating the maximum loan amount you qualify for, based on a thorough review of your finances.
A common mistake and how to avoid it: Waiting until you’ve found a house to get pre-approved. This can lead to disappointment and lost opportunities.

8. Factor in other homeownership costs

What to do: Consider ongoing expenses like homeowners insurance, property taxes, potential HOA fees, and maintenance.
What “good” looks like: A budget that accounts for these costs, ensuring you can comfortably afford the total financial commitment of homeownership.
A common mistake and how to avoid it: Overlooking the long-term costs of home maintenance and repairs. Avoid this by setting aside a small percentage of your income for a home repair fund.

Common mistakes (and what happens if you ignore them)

Mistake	What it causes	Fix
Ignoring your credit score	Higher interest rates, lower borrowing limits, or outright loan denial.	Regularly check credit reports, dispute errors, and pay bills on time.
Overestimating your borrowing power	Financial strain, inability to meet payments, potential foreclosure, and damage to credit.	Be conservative with DTI ratios and prioritize a comfortable monthly payment over the maximum loan amount.
Underestimating closing costs	Needing to scramble for funds, potentially delaying closing or reducing your down payment.	Budget 2-5% of the loan amount for closing costs and get a detailed Loan Estimate from lenders.
Not saving enough for a down payment	Higher monthly payments due to a larger loan, potential PMI, and limited lender options.	Prioritize saving and explore low-down-payment loan programs.
Failing to budget for PITI	Miscalculating affordability, leading to unexpected financial shortfalls each month.	Always include Principal, Interest, Taxes, and Insurance (PITI) in your monthly mortgage payment estimates.
Not getting pre-approved early	Losing out on desirable homes, facing bidding wars with all-cash offers, or missing deadlines.	Get pre-approved before you start seriously house hunting.
Ignoring ongoing homeownership costs	Financial stress, inability to cover unexpected repairs, and difficulty maintaining your home.	Budget for maintenance, repairs, property taxes, and insurance in addition to your mortgage payment.
Not shopping around for lenders	Paying a higher interest rate and fees than necessary, costing thousands over the loan’s life.	Compare offers from multiple lenders to find the best rates and terms.
Taking on new debt before applying	Increasing your DTI, potentially lowering your credit score, and jeopardizing your loan approval.	Avoid significant new purchases or loans during the mortgage application process.
Not understanding loan types	Choosing a loan that doesn’t fit your financial situation, leading to higher costs or missed opportunities.	Research different mortgage types (FHA, VA, Conventional, etc.) and consult with a loan officer.

Decision rules (simple if/then)

• If your DTI is above 43%, then you likely need to reduce debt or increase income to qualify for most mortgages because lenders see this as a high risk.
• If your credit score is below 620, then focus on improving it before applying for a mortgage because you may not qualify or will face very high interest rates.
• If you have less than 3-6 months of living expenses saved, then prioritize building an emergency fund before taking on a mortgage because unexpected events can lead to default.
• If you can afford a 20% down payment, then aim for it to avoid private mortgage insurance (PMI) because PMI adds to your monthly cost without building equity.
• If you are a veteran or active-duty military, then explore VA loans because they often offer no down payment and competitive rates.
• If you are looking at homes in rural areas, then research USDA loans because they may offer no down payment options for eligible borrowers.
• If you have significant high-interest debt (e.g., credit cards), then consider paying it down before a mortgage because it improves your DTI and frees up cash flow.
• If you are unsure about your budget, then use a mortgage affordability calculator and then get pre-approved to get a concrete number.
• If you plan to buy in an area with high property taxes, then factor those costs into your PITI calculation carefully because they can significantly increase your monthly payment.
• If you are self-employed or have variable income, then be prepared for more extensive documentation requirements from lenders because they need to verify your income stability.
• If you have a tight budget but want to buy, then look for homes in less expensive areas or consider a fixer-upper because it can lower your initial purchase price.
• If you are comparing loan offers, then look beyond just the interest rate and consider the Annual Percentage Rate (APR) which includes fees, and compare the total closing costs.

FAQ

How much house can I afford?

This depends on your income, debts, credit score, down payment, and local housing costs. A general rule is to aim for a total housing payment (PITI) that’s no more than 28% of your gross monthly income.

What is a good debt-to-income ratio (DTI) for a mortgage?

Lenders often prefer a DTI of 36% or lower, but many will go up to 43%. A lower DTI indicates you have more disposable income to handle a mortgage payment.

Do I need a 20% down payment?

No, many loan programs allow for lower down payments, such as 3.5% for FHA loans or even 0% for VA or USDA loans for eligible borrowers. However, a 20% down payment typically avoids private mortgage insurance (PMI).

How much are closing costs?

Closing costs typically range from 2% to 5% of the loan amount. These include fees for appraisal, title insurance, loan origination, and more.

What is Private Mortgage Insurance (PMI)?

PMI is an insurance policy that protects the lender if you default on your loan when you put down less than 20% on a conventional mortgage. It adds to your monthly payment.

How does my credit score affect my mortgage?

A higher credit score generally qualifies you for lower interest rates, saving you thousands of dollars over the life of the loan. A low score can lead to higher rates or loan denial.

Can I get pre-approved for a mortgage before I find a house?

Yes, getting pre-approved is highly recommended. It tells you how much a lender is willing to lend you, strengthening your offer when you find a home.

What is an interest rate lock?

An interest rate lock is an agreement with a lender to hold a specific interest rate for a set period while your loan is being processed. This protects you from rising rates.

Should I pay off debt before buying a house?

It’s often a good idea, especially high-interest debt. Paying down debt improves your DTI and can free up cash flow for your mortgage and other expenses.

What this page does NOT cover (and where to go next)

• Specific loan product details and current interest rates (contact lenders for this information).
• The intricacies of mortgage underwriting and specific lender criteria (consult with loan officers).
• Real estate market analysis or home valuation techniques (speak with a real estate agent).
• Detailed tax implications of homeownership, such as mortgage interest deductions (consult a tax professional).
• The legal aspects of real estate transactions (seek advice from a real estate attorney).
• Strategies for optimizing home equity or refinancing options (research these topics further).