Buying a home is one of the largest financial decisions most people make, and the question of affordability sits at the center of it. Not just what a lender will approve you for, but what you can realistically carry without stretching your finances to a point that makes everything else harder.
Those two numbers are often very different. Lenders qualify you based on your income, your debts, and your credit profile. They don't know what your groceries cost, how much you spend on childcare, or what your retirement savings goal looks like. The approval number is a ceiling, not a recommendation.
This guide walks through how to figure out what you can actually afford, and how to think about that number in a way that holds up over time, not just on closing day.
Start with your gross monthly income
Most mortgage affordability guidelines start with your gross income, what you earn before taxes and deductions. That's the number lenders use, and it's the right starting point for understanding what's realistic.
The most widely used benchmark is called the 28/36 rule. It suggests that your monthly housing costs, mortgage payment, property taxes, homeowners insurance, and any HOA fees, should stay at or below 28% of your gross monthly income. Your total debt payments, including housing plus any existing obligations like car loans, student loans, or credit cards, should stay at or below 36%.
These aren't hard limits, and lenders will often approve borrowers who exceed them, particularly the 36% total debt threshold, which some conventional loan programs stretch to 43% or even 45% for strong borrowers. But the 28/36 rule exists for a reason. It reflects a payment level that most households can sustain without crowding out the rest of their financial life.
A straightforward example: if your household earns $8,000 per month gross, the 28% housing guideline puts your target monthly payment at $2,240 or below. At 36%, your total monthly debt including that housing payment should stay under $2,880.
Understand what the monthly payment actually includes
When most people think about a mortgage payment, they think about principal and interest. Those are the core components, but they're rarely the whole number.
Principal and interest make up the base payment, the portion that actually reduces your loan balance over time and compensates the lender for the money borrowed. This is what a mortgage calculator will typically show you.
Property taxes vary significantly by location and are usually collected monthly as part of your payment through an escrow account. In some areas, taxes add a few hundred dollars a month. In others, they can add significantly more. This is one of the most common surprises for first-time buyers who calculated affordability based on principal and interest alone.
Homeowners insurance is required by virtually all lenders and is also typically collected through escrow. Rates depend on the home's value, location, and coverage level.
Private mortgage insurance (PMI) applies if your down payment is less than 20% of the purchase price. PMI typically costs between 0.5% and 1.5% of the loan amount annually, divided into monthly payments. On a $400,000 loan, that's roughly $170 to $500 per month added to your payment, a meaningful number that often gets overlooked in early affordability calculations.
HOA fees, if applicable, are a fixed monthly cost that lenders factor into your total housing expense. These vary widely depending on the community.
Getting an accurate picture of your real monthly payment requires knowing all five of these components, not just principal and interest.
Factor in your down payment and how it shapes the math
The size of your down payment affects your affordability in several ways simultaneously.
A larger down payment means a smaller loan, which means a lower monthly payment. It also means potentially avoiding PMI, which reduces the total monthly cost further. And it can influence the interest rate you're offered, borrowers with more equity in the transaction are generally seen as lower risk.
The traditional benchmark is 20%. At that threshold, you avoid PMI, which has a meaningful effect on monthly costs. But 20% isn't required, and for many buyers in 2026, particularly in higher-cost markets, it represents a significant obstacle.
Conventional loans are available with as little as 3% down for qualified borrowers. FHA loans require 3.5% with a credit score of 580 or higher. VA loans, available to eligible military service members and veterans, often require no down payment at all. USDA loans offer similar terms for buyers in qualifying rural and suburban areas.
The right down payment isn't necessarily the largest one you can manage. Depleting your savings to hit 20% can leave you without an emergency fund in the months after closing, a precarious position when homeownership inevitably brings unexpected costs. Many financial planners suggest targeting a down payment that avoids or minimizes PMI while preserving three to six months of living expenses in reserve.
Know your debt-to-income ratio before a lender calculates it for you
Your debt-to-income ratio, DTI, is one of the primary numbers lenders use to evaluate your application. It compares your monthly debt obligations to your gross monthly income and gives lenders a picture of how much additional payment capacity you have.
Front-end DTI refers to your housing costs alone as a percentage of gross income. Back-end DTI includes all monthly debt payments, housing, car loans, student loans, minimum credit card payments, and any other obligations.
Most conventional loan programs look for a back-end DTI below 43%, though some will go higher for borrowers with strong credit and reserves. FHA loans are generally more flexible on DTI than conventional products.
Knowing your DTI before you apply gives you the opportunity to improve it. Paying down a car loan or credit card balance before applying reduces your monthly obligations and improves the ratio. Avoiding new debt in the months before applying, a new car, a large purchase on credit, keeps it from moving in the wrong direction.
The practical implication: if your DTI is already at or near the upper limits lenders typically accept, your approval may depend more on that number than on your income alone.
Think beyond the mortgage payment
Lenders evaluate whether you can afford the loan. They don't evaluate whether you can afford the home.
Those are different questions. A lender's approval doesn't account for maintenance and repairs, which typically run 1% to 2% of a home's value annually. On a $400,000 home, that's $4,000 to $8,000 per year, money that needs to come from somewhere. It doesn't account for utility costs that may be significantly higher than what you're used to. It doesn't account for furniture, landscaping, or the dozen other costs that come with moving into a new home.
A useful test before committing to a payment level: live on the budget that payment would require for two or three months before you buy. If you're currently paying $1,800 in rent and the new mortgage payment would be $2,600, try saving the $800 difference each month and see how it actually feels. If it's comfortable, that's useful information. If it creates stress or requires cutting things you don't want to cut, that's equally useful information.
Affordability isn't just a math problem. It's a quality of life question.
Use current rates to ground your estimates
Mortgage rates in 2026 remain a key variable in any affordability calculation. Even small differences in rate have a significant effect on the monthly payment and total cost over the life of the loan.
On a $350,000 30-year mortgage, the difference between a 6.0% and a 6.5% rate is roughly $114 per month, and over $40,000 in total interest over the life of the loan. That half-point difference can meaningfully affect what price range is realistic for your budget.
Because rates shift regularly in response to economic conditions and Federal Reserve policy, any estimate you run today should be stress-tested against a slightly higher rate. If your budget works at 6.5% but becomes uncomfortably tight at 7%, that's worth knowing before you're under contract on a home.
Getting pre-approved, rather than just pre-qualified, gives you an actual rate offer from a lender based on your real financial profile, which makes your affordability calculation significantly more accurate than any estimate built on assumed rates.
A simple starting framework
If you're not sure where to begin, a few rough calculations can help orient you before you go deeper.
Multiply your target home price by 0.005 to get a rough estimate of your monthly principal and interest payment at a 6% to 6.5% rate on a 30-year loan.
Add estimated taxes, insurance, and PMI if applicable.
Compare that total to 28% of your gross monthly income. If it's comfortably below, your target price is likely in range. If it's above, adjusting the price or increasing your down payment can bring it back into alignment.
That's a starting point, not a final answer. But it gives you a number to work with before you're sitting across from a lender.
What it comes down to
The most useful definition of affordability isn't how much a bank will lend you. It's the payment level that lets you own the home without sacrificing the rest of your financial life, your emergency fund, your retirement contributions, your ability to handle the unexpected without going into debt.
In 2026, with rates still meaningfully above where they were a few years ago, being realistic about that number matters more than it did when borrowing was cheaper. The right home at the right payment is a better outcome than the biggest home your approval letter allows.
If you're ready to run the numbers on your specific situation, start with what you can comfortably put toward housing each month, then work backward to the price range that supports it.
