Find out what you can afford — before you make an offer.

Your lender's calculation uses your gross income and minimum debt payments. It does not include your actual monthly spending, your utility bills, your maintenance reserve, your first-year move-in costs, or the cash you need in reserve after closing. The federal rules that govern mortgage qualification do not require lenders to evaluate post-purchase affordability. This calculator does. The gap between the two numbers reflects the costs the approval process excludes.

DTI is your total monthly debt payments divided by your gross monthly income, expressed as a percentage. It is the primary metric lenders use to evaluate loan applications. Conventional loans typically allow up to 43% back-end DTI — meaning your total monthly debts including the new mortgage cannot exceed 43% of your gross monthly income. This calculator uses 36% for conventional loans as a more conservative threshold. The difference matters: at 43% DTI on a $120,000 income, the loan amount qualified for is roughly $70,000 higher than at 36% DTI.

Source: Consumer Financial Protection Bureau, "Ability to Repay and Qualified Mortgage Rule."

Pre-qualification is a lender's estimate based on what you tell them — no verification, no credit pull, no commitment. Pre-approval involves a hard credit inquiry, income and asset verification, and a conditional commitment to lend a specific amount. Neither one is a measure of post-purchase affordability. Both indicate that a lender is willing to extend credit under specific conditions. This calculator is a planning tool that includes the costs the lender's approval process does not.

The difference between a 760 score and a 680 score on a $400,000 loan at current rates is approximately $150–$200 per month — roughly $54,000 over the life of a 30-year loan. A score below 620 typically disqualifies you from conventional financing entirely. This calculator adjusts the rate assumption by credit tier so the output reflects the difference. Credit scores are available free at AnnualCreditReport.com.

Source: Consumer Financial Protection Bureau, "How Credit Scores Affect the Price of Credit."

Conventional loans: 620 minimum, though rates improve significantly above 700. FHA (Federal Housing Administration) loans: 580 minimum with 3.5% down; 500 minimum with 10% down. VA (Department of Veterans Affairs) loans: no VA-set minimum, though most lenders require 620. USDA (U.S. Department of Agriculture) loans: typically 640. Scores below 700 cost measurably more over the life of the loan. The calculator adjusts your rate by credit tier — the output shows what that costs on a monthly and lifetime basis.

Source: Federal Housing Finance Agency; HUD Mortgagee Letter 2010-11.

Step 1 uses gross income because DTI (Debt-to-Income) ratios are calculated against gross pay industry-wide — that's not a choice this calculator makes, it's how lenders work. Step 2 uses take-home pay because that's the number that determines what you can actually spend once you own the home. Using the same figure for both would make one of the two numbers wrong. The gap between what your lender approves and what you can actually sustain often comes from exactly this distinction.

Property taxes, homeowners insurance, PMI (Private Mortgage Insurance) if your down payment is under 20%, HOA (Homeowners Association) fees, maintenance reserve, utilities, and first-year move-in costs. On a $400,000 home in a typical Midwest or mid-Atlantic market, those omitted costs add $1,200–$2,000 per month to the mortgage payment shown by a standard calculator.

Source: Harvard Joint Center for Housing Studies, "Improving America's Housing 2023."

PMI protects the lender, not the borrower, in the event of default. It is required on conventional loans when the down payment is under 20% of the purchase price. Typical annual cost: 0.5%–1.5% of the loan amount. On a $380,000 loan at 0.8% PMI, that is $3,040 per year — $253 per month — and builds no equity for the borrower. PMI drops automatically when 22% equity is reached by original amortization schedule, or can be requested for removal at 20% equity. At standard amortization on a 30-year loan, reaching 20% equity takes roughly 8–11 years without additional principal payments.

Source: Urban Institute Housing Finance Policy Center, "PMI Market Structure, Products, and Performance," 2024.

The convention: budget 1% of a home's value annually for maintenance and repairs. On a $400,000 home, that is $4,000 per year, or $333 per month. Older homes carry higher deferred maintenance risk — homes built before 1980 typically require more — and this calculator adjusts the reserve estimate by home age. The 1% rule is an average across home ages and conditions: a recently renovated home may need less; a 60-year-old home with original systems will likely need more.

Source: Harvard Joint Center for Housing Studies; National Association of Home Builders maintenance cost research.

In most states, yes — and the change can be significant. Many states reassess property at the sale price. If the previous owner bought the home 15 years ago at $220,000 and you buy it at $450,000, your tax bill will be calculated on $450,000. In Cook County, Illinois, reassessment can take 1–3 years to take effect, which is why some buyers face a tax bill that doubles in year two or three of ownership. This calculator uses your purchase price and zip code to estimate the post-sale effective tax rate — not the current owner's bill, which is the figure displayed on Zillow and Redfin listings.

Source: Tax Foundation, "State-by-State Property Tax Burden," 2024; U.S. Census Bureau American Community Survey county-level effective tax rate data.

The FDIC recommends maintaining at least six months of living expenses as an emergency reserve. This calculator sets your reserve floor as the greater of 5% of your target purchase price or six months of the monthly lifestyle costs you entered — a conservative, CFPB-aligned baseline, not a flat number. The reasoning: the down payment depletes savings, closing costs take another $8,000–$22,000, and first-year move-in costs (window treatments, furniture, appliances not included, immediate repairs from the inspection report) add another $10,000–$30,000. A buyer who closes with $0 in cash and encounters a $12,000 furnace replacement in month three has a financial gap with no buffer.

Source: FDIC emergency savings guidance; National Association of Realtors, "Profile of Home Buyers and Sellers," 2023.

Not always. Three numbers determine the answer: PMI cost if the down payment is below 20%, rate improvement from crossing an LTV (Loan-to-Value) tier threshold, and cash reserve after closing. A buyer who puts 20% down and has $0 left in reserve is financially more exposed than a buyer who puts 15% down and keeps $20,000 in reserve. The calculator allows both scenarios to be modeled side by side.

Conventional loans: as little as 3% down with PMI. FHA loans: 3.5% down with a 580+ credit score. VA loans: 0% down for eligible veterans and active military — no PMI required. USDA loans: 0% down for eligible rural properties with income limits. Each program has property type restrictions, loan limits that vary by county, and income eligibility requirements. The calculator shows estimated qualification by loan type — a lender confirms eligibility and final terms.

Source: Federal Housing Finance Agency conforming loan limits; HUD FHA loan requirements; VA Lenders Handbook; USDA Rural Development guidelines.

Closing costs are fees due at the closing table on top of the down payment — typically 2%–5% of the purchase price. On a $400,000 home that is $8,000–$20,000 in cash, due the same day as the down payment. Components include loan origination fees, title insurance, appraisal, escrow setup, recording fees, and transfer taxes that vary significantly by state. New York City buyers can pay 2%+ in transfer taxes alone. Florida has no state transfer tax. This calculator uses 3% as a conservative default. Federal law requires lenders to provide a Loan Estimate within three business days of application showing the actual itemized costs.

Source: Consumer Financial Protection Bureau, TRID (Truth in Lending Act/RESPA Integrated Disclosure) requirements.

Using a conventional 36% DTI (Debt-to-Income ratio), no other debt, 10% down, and current rates: roughly $85,000–$95,000 gross annual income. Existing debt payments raise that number proportionally. Factoring in the full cost picture — taxes, insurance, PMI, maintenance, utilities — the income threshold for a $400,000 home with cushion is closer to $100,000–$110,000. The salary-to-home-price relationship shifts meaningfully by zip code due to property tax variation alone. This calculator runs the math with the user's actual inputs rather than national averages.

Source: HomeMath analysis using FRED rate data, U.S. Census Bureau ACS property tax data, and Insurance Information Institute benchmarks.

More accurate than a standard mortgage calculator for planning purposes — less accurate than a conversation with a lender for approval purposes. This calculator uses zip code for property tax and insurance estimates, credit tier for rate assumptions, and home age for maintenance reserve — inputs most affordability calculators do not include. The output is a planning number, not a commitment. Actual monthly costs will vary based on specific loan terms, the property purchased, and local market conditions. Every assumption used in the calculation is visible.

The calculator is most useful in the planning phase, before a lender conversation defines the affordability ceiling. The output is the buyer's own number based on their own inputs — including the costs the lender's approval calculation excludes. Comparing the two numbers (the calculator's output and the lender's offer) surfaces the cost of operating at the lender's ceiling versus the calculator's threshold.

Three inputs change the number: income, debt, and target price. The calculator allows all three scenarios to be modeled. The gap between current inputs and the desired purchase price does not change after closing — it persists as a structural monthly shortfall. A home purchased above the calculator's threshold does not become more affordable over time without one of those three inputs changing.

Include it if the partner will be on the loan — enter combined gross annual income and combined monthly debt payments. If the partner will not be on the loan, use only the qualifying borrower's income. A loan in one name on a two-income household has lower purchasing power but can be the right approach when one partner has significantly better credit or cleaner income documentation. A lender can run both scenarios.

Daily. This calculator pulls the current 30-year fixed mortgage rate directly from the FRED API (Federal Reserve Bank of St. Louis, series MORTGAGE30US), which mirrors the Freddie Mac Primary Mortgage Market Survey published weekly. The rate displayed reflects the most recent data available. A 0.25% rate difference on a $380,000 loan is approximately $570 per year — a difference worth comparing across lenders.

Source: Freddie Mac Primary Mortgage Market Survey via Federal Reserve Bank of St. Louis FRED API.

The personalized affordability report (email required) provides the full breakdown — including the calculator's number, the lender's likely maximum, the monthly cost breakdown, and the cash position after closing. The report is a planning document for use alongside a lender conversation, an offer decision, or a budget review. The point is comparison: the gap between what a lender will approve and what the math here produces is the cost of buying at the lender's ceiling.