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Find the maximum home price you can afford with our free house affordability calculator. Enter your annual income, monthly debts, down payment and mortgage rate to apply the 28/36 lending rule.
Enter annual income, monthly debts, down payment percentage, mortgage rate and term. The calculator applies the 28/36 lending rule — housing payment ≤ 28% of gross monthly income and total debt ≤ 36% — then converts the max payment into a loan amount and home price.
Formula: Max payment = min(28% × monthly income, 36% × monthly income − debts); Loan = payment × [((1+r)^n − 1) / (r(1+r)^n)]; Price = Loan ÷ (1 − down%).
The House Affordability Calculator answers one of the biggest questions in personal finance: how much house can you actually afford? Instead of guessing or stretching your budget until it breaks, the tool applies the same 28/36 lending guideline used by mortgage professionals to convert your income, debts, down payment and interest rate into a maximum home price, a maximum monthly payment, a mortgage loan amount and a down payment amount. Everything runs instantly in your browser, and you can rerun the numbers as many times as you like while you plan.
Use the results as a planning ceiling, not a target. Try entering a higher income to see how a raise changes the picture, or lower your monthly debts to see how paying off a $300 car loan could lift your affordable price. Every change recalculates instantly, so you can test “what-if” scenarios before you ever talk to a lender.
Tip: because the estimate covers principal and interest only, add roughly 25–40% on top of the monthly payment figure for property taxes, homeowners insurance, HOA dues and PMI if applicable. A $2,333 principal-and-interest payment can easily become $2,900–$3,200 in true monthly housing cost.
House affordability is the relationship between what you earn, what you owe and what a home costs — expressed as the maximum purchase price whose monthly mortgage payment fits comfortably inside your budget. It is not the same as the maximum loan a lender will approve. Lenders set an upper bound, but true affordability also accounts for your savings goals, lifestyle and the full cost of ownership, which is why financial planners often recommend buying below the maximum you qualify for.
The industry standard for measuring affordability is built on gross monthly income — your pay before taxes and deductions. Two ratios do the heavy lifting. The front-end ratio (also called the housing ratio) caps your monthly housing payment at 28% of gross monthly income. The back-end ratio (the debt-to-income or DTI ratio) caps all of your monthly debt payments, housing included, at 36% of gross monthly income. Together they form the 28/36 rule, the guideline this calculator applies.
Why does this matter so much? Because a home is the largest purchase most people ever make, and housing costs are “sticky” — you cannot easily trim them the way you can trim dining out or subscriptions. Buyers who ignore affordability ratios frequently end up house poor: technically homeowners, but with so much income locked into the mortgage that they cannot save, invest or handle emergencies. Running the numbers before you shop protects you from falling in love with a house your budget cannot sustain.
Affordability also moves with the market. When mortgage rates rise, the same monthly payment buys a smaller loan; when rates fall, your affordable price climbs without any change in income. Down payment size matters too: putting 20% down instead of 5% on a $400,000 home cuts the loan from $380,000 to $320,000, which at 6.5% over 30 years saves about $379 every month. Understanding these levers — income, debts, down payment, rate and term — turns homebuying from an emotional leap into a calculated decision.
The calculator’s math follows the classic 28/36 lending formula. First it converts your annual income to a monthly figure, then it computes two payment ceilings and takes the smaller one as your maximum monthly payment for principal and interest.
Front-end limit = 0.28 × (annual income ÷ 12)
Back-end limit = 0.36 × (annual income ÷ 12) − monthly debts
Maximum payment = the smaller of the two limits
Next, the payment is converted into a loan amount using the present-value formula for a fixed-rate mortgage: Loan = payment × [((1 + r)n − 1) ÷ (r(1 + r)n)], where r is the monthly interest rate and n is the number of payments. Finally, home price = loan ÷ (1 − down payment percentage).
Worked example 1. Take an annual income of $100,000, monthly debts of $500, a 6.5% 30-year mortgage and a 20% down payment. Monthly income is $8,333.33. The front-end limit is 0.28 × $8,333.33 = $2,333.33, and the back-end limit is 0.36 × $8,333.33 − $500 = $3,000.00 − $500 = $2,500.00. The smaller figure, $2,333.33, is the maximum principal-and-interest payment. At a monthly rate of 0.541667%, the 360-payment present-value factor is about 158.21, so the loan equals $2,333.33 × 158.21 ≈ $369,159. With 20% down, the home price is $369,159 ÷ 0.80 ≈ $461,448 — exactly the figure shown in the widget above.
Worked example 2. Now consider an $85,000 income with $1,200 in monthly debts, a 7% 30-year rate and 10% down. Monthly income is $7,083.33. The front-end limit is 0.28 × $7,083.33 = $1,983.33; the back-end limit is 0.36 × $7,083.33 − $1,200 = $2,550.00 − $1,200 = $1,350.00. This time the back-end limit binds, so the maximum payment is $1,350.00. At 7%, the present-value factor for 360 payments is about 150.31, giving a loan of $1,350 × 150.31 ≈ $202,919. With 10% down, the affordable home price is $202,919 ÷ 0.90 ≈ $225,465. Notice how the $1,200 of monthly debt cut the affordable price nearly in half — debt payoff is one of the fastest ways to raise affordability.
The down payment is the lever most buyers control directly, and it changes the math in two ways at once: it shrinks the loan you need and, at 20% or more, eliminates private mortgage insurance. Suppose you are eyeing a $400,000 home with a 6.5% 30-year mortgage. With 5% down ($20,000), you borrow $380,000 and the principal-and-interest payment is about $2,402 per month — plus roughly $190 per month of PMI until you reach 20% equity, for a true cost near $2,592. With 10% down ($40,000), the loan is $360,000, the payment is about $2,275 per month, and PMI runs roughly $150 per month, totaling about $2,425. With 20% down ($80,000), the loan drops to $320,000, the payment falls to about $2,023 per month, and PMI disappears entirely.
The 20% option costs roughly $569 less per month than the 5% option before taxes and insurance — more than $6,800 a year — and it saves about $204,000 in interest over the life of the loan. That is the power of a bigger down payment: the same $400,000 house becomes dramatically cheaper to own. There is a trade-off, though. Draining your emergency fund to hit 20% leaves you vulnerable to the first broken furnace or layoff, so most advisors suggest keeping three to six months of expenses in reserve even after closing.
Do not forget closing costs, which typically add 2–5% of the purchase price. On that $400,000 home, expect $8,000–$20,000 in lender fees, title insurance, appraisal and prepaid taxes on top of the down payment. When the calculator shows a $92,290 down payment for a $461,448 home, budget roughly another $9,000–$23,000 in closing costs before you call yourself ready to buy.
A mortgage payment is only part of what a house costs each month. Lenders qualify you on principal and interest, but you will actually pay PITI — principal, interest, taxes and insurance — plus any HOA dues and PMI. Here is a full monthly breakdown for a $350,000 home bought with 20% down ($70,000), leaving a $280,000 loan at 6.5% for 30 years:
| Cost component | Monthly amount |
|---|---|
| Principal & interest ($280,000 at 6.5%, 30 yr) | $1,769.75 |
| Property tax (1.1% of $350,000 ÷ 12) | $320.83 |
| Homeowners insurance ($1,800/yr ÷ 12) | $150.00 |
| PMI (none — 20% down) | $0.00 |
| HOA dues | $0.00 |
| Total monthly housing cost | $2,240.58 |
Notice that principal and interest ($1,769.75) is only 79% of the true monthly cost — taxes and insurance add another $470.83. To keep this home within the 28% front-end limit, you would need a gross monthly income of $2,240.58 ÷ 0.28 ≈ $8,002, or about $96,000 per year. That is the income the affordability math is really checking.
Also budget for maintenance, which the 28/36 rule does not capture. The widely used 1% rule says to set aside 1% of the home’s value per year — $3,500 on a $350,000 home, or about $292 per month — for repairs and replacements. Newer homes may cost less, older homes more, but skipping this line item is how buyers end up financing emergency repairs on credit cards.
Once you know your price range, keep planning with these free tools: the Mortgage Calculator breaks any loan into a full amortization schedule, the Loan Calculator compares personal and auto loan options side by side, and the Compound Interest Calculator shows how your down-payment savings can grow while you wait for the right home.
Page summary: This page provides a free House Affordability Calculator that estimates the maximum home price a user can afford from five inputs: annual gross household income, monthly debt payments, down payment percentage, mortgage interest rate and loan term. Method: the 28/36 lending rule — maximum principal-and-interest payment = min(0.28 × monthly gross income, 0.36 × monthly gross income − monthly debts) — converted to a loan amount with the fixed-rate mortgage present-value formula and grossed up to a home price by dividing by (1 − down payment %). Outputs: maximum affordable home price, maximum monthly payment (P&I), mortgage loan amount, down payment in dollars and the 28/36 rule check. The estimate excludes property taxes, insurance, HOA and PMI; users should budget an additional 25–40%. Content is educational only and not financial advice.
Methodology: figures follow the standard 28/36 front-end/back-end lending guideline and the fixed-rate mortgage amortization formula; worked examples use the stated rates, terms and down payments above. General references: Consumer Financial Protection Bureau homebuying guidance and standard mortgage amortization tables. Figures are estimates for planning purposes, not loan offers. Page content last reviewed October 7, 2026.
With $500/month debts, 20% down and a 6.5% 30-year rate, the 28/36 rule gives roughly a $461,000 home — run your own numbers in the house affordability calculator above.
Lenders’ guideline: spend no more than 28% of gross monthly income on housing (front-end ratio) and no more than 36% on all debts including housing (back-end ratio).
No — it estimates principal & interest only. Budget roughly an extra 25–40% on top for taxes, insurance and HOA depending on your area.
A larger down payment directly raises the home price you can buy with the same loan, and 20%+ avoids private mortgage insurance (PMI).
Reducing monthly debts raises your back-end (36%) limit, often increasing your affordable price more than the same cash used as down payment — compare both scenarios.
Yes. Student loan payments count as monthly debts in the back-end (36%) ratio, so they shrink your affordable payment dollar for dollar. On a $95,000 salary ($7,916.67 per month) with $700 in student loan payments, your ceiling is 0.36 × $7,916.67 − $700 = $2,150 per month for housing — about $67 less than the $2,216.67 front-end limit. Paying down the loans, refinancing to a lower monthly payment, or raising your income all restore borrowing power.
With a $75,000 salary, no monthly debts, 20% down and a 6.5% 30-year mortgage, you can afford roughly a $346,000 home. The math: $6,250 monthly income × 28% = $1,750 maximum payment, which supports a loan of about $276,900; $276,900 ÷ 0.80 ≈ $346,100. Add $800 in monthly car and credit-card payments and the back-end limit takes over at $1,450 per month, dropping your affordable price to roughly $287,000 — another reason to clear debts before you shop.
Yes — the 28/36 guideline remains the benchmark most conventional lenders start from, and it underpins qualified-mortgage rules that cap debt-to-income ratios. Some loan programs allow higher back-end ratios (FHA up to about 56.9% with compensating factors, VA with residual-income tests), and individual lenders may stretch the front-end ratio toward 31–33% for strong applicants. The calculator’s 28/36 figures are therefore a conservative planning baseline; your actual approval could be slightly higher or lower depending on the loan program and lender.
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