"How much house can I afford?" is the question every home search should start with — and the honest answer usually differs from what a lender will approve you for. Getting this number right before you start browsing listings prevents the most common and most painful home-buying mistake: falling in love with a price point your actual finances cannot sustainably support. This guide walks through the complete picture, not just the mortgage payment lenders quote, but the full cost of ownership that determines whether a home purchase strengthens your finances or strains them for years to come.
Quick answer: Most financial guidelines put your target home price between 2.5x and 4x your gross annual household income, depending on your down payment, debt load, and local interest rates. On a $90,000 income with a 10% down payment at 2026 rates, that typically lands between $290,000 and $360,000.
The 28/36 rule lenders actually use
Mortgage lenders qualify you using two debt-to-income ratios that work together. The front-end ratio caps your housing payment — principal, interest, property taxes, homeowners insurance, and HOA dues, together abbreviated as PITIA — at 28% of your gross monthly income. The back-end ratio caps your total monthly debt obligations, including the new mortgage payment plus every other recurring debt you carry (car loans, student loans, credit card minimums, personal loans), at 36% of gross monthly income. Whichever of these two ratios produces the lower dollar figure becomes your actual practical ceiling, since a lender will not approve a loan that violates either limit.
These are guidelines rather than hard legal limits, and lender flexibility varies considerably. Some conventional lenders will stretch to 43% or even 45% back-end DTI for borrowers who present strong compensating factors: excellent credit scores, several months of cash reserves after closing, a stable long-tenure job, or a larger-than-typical down payment. FHA loans, in particular, are often more flexible on DTI than conventional financing, sometimes approving borrowers above 50% back-end DTI with sufficiently strong credit. But qualifying for a higher payment and being genuinely comfortable carrying it every month for the next 15-30 years are two very different things, which is precisely why so many financial planners recommend treating the lender-approved maximum as a ceiling rather than a target.
It is worth understanding exactly why lenders use 28% and 36% specifically rather than some other number. These thresholds emerged from decades of mortgage default data: borrowers whose housing costs exceeded roughly 28% of income showed measurably higher default rates, especially when combined with total debt loads above 36%. The ratios are not arbitrary tradition — they reflect actuarial reality about how much housing cost a typical household budget can absorb before other expenses (food, transportation, healthcare, savings) get squeezed to an unsustainable degree.
Why the "affordable" number is often lower than the "approved" number
A lender calculates what you qualify for based strictly on income and existing debt obligations — the DTI math says nothing whatsoever about your other financial goals or life circumstances. Retirement contributions, building or maintaining an emergency fund, childcare costs, healthcare expenses, existing lifestyle spending, and simply the margin needed to absorb unexpected costs all sit completely outside the DTI calculation. A lender does not ask whether you are contributing to a 401(k), whether you have three children in daycare, or whether your car will need replacing in two years — yet all of these materially affect what payment you can actually sustain without financial stress.
Because of this gap, many housing counselors and fee-only financial planners suggest treating the lender-approved number strictly as a ceiling, never as a target to aim for. A useful practical sanity check: if buying at your maximum approved price would leave you unable to continue saving toward retirement at your current rate, or would require abandoning or significantly shrinking your emergency fund, the number is too high for your actual financial comfort — regardless of what a lender is willing to approve on paper. Consider building your real target from the bottom up: start with your current take-home pay, subtract your non-negotiable savings goals and existing debt payments, and see what housing budget remains, rather than starting from the lender ceiling and working down.
A related trap worth naming explicitly: pre-approval letters often show the maximum loan amount, not a recommended amount, and the psychological pull of "I am approved for $450,000" can quietly shift a buyer's search upward even when their comfortable budget was closer to $380,000. Anchoring your search to your own calculated comfortable number, and treating the pre-approval figure as background information rather than a target, keeps the search focused on homes you will be glad you bought five years later.
The hidden costs that change the real number
Home price and the mortgage payment quoted by a lender are only part of the true cost of ownership. Maintenance typically runs 1-2% of home value annually — commonly $4,000 to $8,000 per year on a $400,000 home, covering everything from routine HVAC servicing to the eventual roof replacement every 20-25 years. Utilities on a larger single-family home run meaningfully higher than a comparable apartment, particularly heating and cooling costs in climates with real seasonal extremes. HOA dues, where applicable, add a fixed monthly cost that can range from negligible to several hundred dollars, and unlike a mortgage payment, HOA dues are not fixed for the life of the loan — they can and do increase.
First-year move-in costs also catch many new buyers by surprise: furniture for rooms that were previously empty in a rental, window treatments, appliances the previous owner took with them, landscaping equipment, and the inevitable list of small repairs that surface once you actually live in the space day to day. Building a realistic total cost of ownership before committing to a price range, not just the mortgage principal and interest, prevents the most common source of new-homeowner financial stress in the first 12-18 months after closing.
How down payment size changes your affordable range
Every dollar of down payment does double duty in the affordability calculation. First, it directly and proportionally reduces the loan amount you need to finance, which lowers the principal and interest portion of your monthly payment. Second, once your down payment crosses the 20% threshold, it eliminates private mortgage insurance (PMI) entirely on a conventional loan, which removes an additional recurring monthly cost that otherwise persists until you reach 78-80% loan-to-value through paydown or appreciation.
Moving from 5% down to 20% down on a $350,000 home typically frees up somewhere between $300 and $500 of monthly budget once you combine the smaller loan balance with the eliminated PMI. That freed-up budget translates directly into either a meaningfully higher affordable price if you choose to stretch your search upward, or into a materially lower, more comfortable monthly payment if you keep your target price the same and simply enjoy the added breathing room. The tradeoff, of course, is that a larger down payment ties up more cash that might otherwise sit in an emergency fund or continue growing in an investment account — the right balance depends on your broader financial picture, not affordability math alone.
Regional cost of living changes everything
A $350,000 affordability ceiling means something entirely different in Cleveland, Ohio than it does in San Francisco, California, or even between two suburbs thirty minutes apart in the same metro area. In high-cost markets, the same income and the same DTI math supports a meaningfully smaller home, a condo instead of a single-family house, or a longer commute in exchange for a more affordable suburb further from the urban core. National affordability guidelines like the ones in this article are a useful starting framework for the math, but they are never a substitute for actually checking what your calculated target price buys on current local listings in the specific neighborhoods you are considering.
This is particularly important because property tax rates, insurance costs, and even typical HOA structures vary so widely by region that the "hidden costs" table above can understate or overstate your real numbers by a meaningful margin depending on where you are buying. A buyer targeting coastal Florida should expect insurance costs well above the national average due to hurricane and flood risk; a buyer in a state with no local property tax caps may see tax bills climb faster than expected after a reassessment. Pulling actual local tax rates and insurance quotes before finalizing your target price range is worth the extra hour it takes.
A step-by-step approach to finding your real number
Start by calculating your gross monthly income and listing every recurring debt payment you currently carry — car loans, student loans, credit cards, personal loans, any child support or alimony obligations. Apply the 28% and 36% caps to find your lender-qualifying ceiling. Then, separately, build a bottom-up budget: what do you actually spend monthly on everything that is not housing, what do you want to continue saving toward retirement and other goals, and what remains as a genuinely comfortable housing budget. Compare the two numbers. If the bottom-up number is lower than the lender ceiling, as it often is, that lower number is your real target — not the ceiling.
Finally, run that target payment through a full affordability calculator that accounts for your specific down payment, local tax rate, and insurance estimate, rather than relying on a flat income multiplier. The difference between a rough 3x-income rule of thumb and a properly calculated number, personalized to your actual down payment and debt load, is often tens of thousands of dollars in either direction.
Use the Home Affordability Calculator to get your exact number based on your income, debts, and down payment, then check the full monthly breakdown with the Mortgage Calculator.
How credit score affects your affordable price indirectly
Credit score does not appear in the 28/36 DTI formula directly, but it changes your affordable price substantially through the interest rate you are offered. A borrower with a 760+ credit score might receive a rate half a percentage point or more below a borrower in the 660-699 range, and that rate difference directly changes how large a loan a given monthly payment can support. On a $2,200 monthly housing budget, a 0.5% rate improvement can support roughly $25,000-$35,000 more in loan amount at the same payment — meaning credit score optimization before you start house hunting is one of the highest-leverage things a prospective buyer can do.
This is why many mortgage professionals recommend checking your credit report and score at least six months before beginning a serious home search, giving enough time to pay down credit card balances, dispute any errors, and let your utilization ratio improve before a lender pulls your file. A modest, achievable credit score improvement in that window can shift your affordable price range meaningfully upward without changing your income or savings at all.
Common affordability mistakes first-time buyers make
The single most common mistake is anchoring to the pre-approval maximum rather than a personally calculated comfortable budget, as discussed above. A close second is underestimating closing costs, which typically run 2-5% of the loan amount and must be paid in cash on top of the down payment — a buyer who has saved exactly 10% down and nothing more can find themselves short at the closing table. A third common mistake is failing to account for the gap between a rental security deposit (often one month's rent) and the much larger cash requirement of a home purchase down payment plus closing costs, which can catch buyers moving directly from renting off guard.
A fourth mistake worth naming: treating the monthly mortgage payment as the full cost of the transition from renting. Many renters do not budget for the jump from a landlord-covered maintenance model to bearing 100% of repair costs themselves, or for the increase in utility costs that often comes with more square footage. Building a full post-purchase monthly budget, not just comparing the new mortgage payment to the old rent payment, avoids an unpleasant surprise in the first few months of ownership.
When it makes sense to buy below your calculated maximum
Buying meaningfully below your calculated affordability ceiling is a deliberate strategy for many financially disciplined buyers, and it comes with real advantages beyond simple caution. A lower payment relative to income creates faster equity accumulation as a share of your budget, more flexibility to handle a job change or income disruption without immediate housing stress, and room to continue funding retirement accounts and other goals at full strength rather than pausing them during the mortgage years. Some buyers deliberately target 20-22% of gross income for housing rather than the full 28% ceiling specifically to preserve this flexibility.
This approach is particularly worth considering for buyers in variable-income situations — commission-based sales roles, self-employment, or industries with cyclical layoff risk — where the DTI calculation based on a snapshot income figure may not reflect the real month-to-month variability the household will actually experience. In these cases, calculating affordability against a conservative, lower-than-current income estimate provides a more realistic and durable target.
Putting it all together: a worked example
Consider a dual-income household earning $105,000 combined gross annual income, carrying a $380/month car payment and $200/month in student loan payments, with $35,000 saved for a down payment. The 28% housing cap on $8,750 monthly gross income is $2,450. The 36% total debt cap, minus the $580 in existing debts, is $2,570. The lower figure, $2,450, becomes the housing budget ceiling. Working backward through a mortgage calculator at a 6.8% rate over 30 years, that payment supports a loan of roughly $310,000, and combined with the $35,000 down payment, a target home price near $345,000 — before accounting for whether this couple wants to spend right up to that ceiling or preserve some margin.
Applying the bottom-up check described earlier, if this household's actual budget shows they are comfortable dedicating $2,100/month to housing rather than the full $2,450 lender ceiling — preserving more room for retirement contributions and a healthy emergency fund — their real target price drops to roughly $300,000, a meaningful $45,000 lower than the lender-approved figure. Neither number is wrong; they answer different questions. The lender number answers "what will I qualify for," while the bottom-up number answers "what will I be comfortable paying every month for the next three decades," and the second question is ultimately the one that determines whether the purchase feels like a smart decision five years later.
How rising rates change the affordability math
Interest rate movements have a larger effect on affordability than most buyers expect, because the relationship between rate and loan amount is not linear at the payment level. A 1 percentage point rate increase on a 30-year loan typically reduces the loan amount a fixed monthly payment can support by roughly 10-11%. That means the same $2,450 monthly housing budget that supports a $310,000 loan at 6.8% would support only about $278,000 at 7.8% — a $32,000 swing in affordable loan amount from a single point of rate movement, with no change whatsoever in the buyer's income or savings.
This is why affordability calculations should always be run against current, not historical, interest rates, and why buyers who calculated their budget a year or two ago should re-run the numbers before resuming a search if rates have moved meaningfully since. It is also a strong argument for locking a rate once you are under contract, since even a modest rate increase between application and closing can shift the numbers enough to affect the deal, and in some cases enough to require re-qualifying at a lower loan amount than originally approved.