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Home Affordability Calculator

Estimate the maximum home price you can afford based on your annual income, monthly debts, down payment, interest rate, and desired debt-to-income ratio. See a breakdown at different DTI levels to understand your options.

"How much house can I afford?" is the first question of any home purchase, and lenders answer it with a single number: the maximum monthly housing payment that fits inside your debt-to-income (DTI) ratio. This calculator reverses the mortgage-payment math — instead of asking what a given home price costs per month, it asks what home price corresponds to a target monthly DTI.

The standard limits used by U.S. lenders are the 28/36 rule: housing costs (PITI) should stay under 28% of gross monthly income, and total debt payments (PITI plus all other debt) should stay under 36%. Some loan programs allow higher — FHA loans can go to 43% or higher, qualifying mortgages can stretch to 45–50% with strong compensating factors — but those are limits, not targets. Most financial planners suggest staying meaningfully below the cap.

Use this calculator to find a ceiling, not a target. Buying right at your maximum approval leaves no buffer for repairs, job loss, or rising taxes/insurance.

Inputs

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Results

Max Home Price

$300,915

Max Loan Amount

$260,915

Monthly PITI

$2,050

DTI Ratio

36.0%

Max Home Price by DTI Ratio

Monthly Payment Breakdown

Affordability by DTI Ratio

DTI %Max MonthlyMax LoanMax Home Price
28.00%$1,483.33$182,617.56$222,617.56
30.00%$1,625.00$202,191.96$242,191.96
32.00%$1,766.67$221,766.35$261,766.35
34.00%$1,908.33$241,340.74$281,340.74
36.00%$2,050.00$260,915.13$300,915.13
38.00%$2,191.67$280,489.53$320,489.53
40.00%$2,333.33$300,063.92$340,063.92
42.00%$2,475.00$319,638.31$359,638.31
44.00%$2,616.67$339,212.70$379,212.70
46.00%$2,758.33$358,787.09$398,787.09
48.00%$2,900.00$378,361.49$418,361.49
50.00%$3,041.67$397,935.88$437,935.88
Last updated: Reviewed by the CalcMountain editorial team

Formula

Maximum monthly housing payment (PITI) allowed: Max PITI = (Annual income / 12) × DTI ratio − Monthly debts Maximum P&I within that envelope: Max P&I = Max PITI − (Property tax + Insurance)/12 Max loan amount (reverse-amortization): L = Max P&I × [ (1+r)^n − 1 ] / [ r(1+r)^n ] Max home price: Max price = L + Down payment Where: r = Monthly rate (APR/12) n = Total monthly payments (years × 12) Example: $85K income, $500/mo other debts, 6.5% rate, 30-yr term, 36% DTI cap, $40K down, 1.1% property tax, $1,500/yr insurance Monthly income: $7,083 Max PITI envelope: 7,083 × 0.36 − 500 = $2,050 Subtract taxes/insurance (varies with price — iterates) Solves to: max price ≈ $295,000

How to use this calculator

  1. Enter your gross annual income (before tax). For two-income households, combine both incomes if both will be on the loan.
  2. Enter monthly debt payments — car loans, student loans, minimum credit card payments, alimony, child support. Don't include rent (it disappears) or utilities (not counted by lenders).
  3. Enter your planned down payment in dollars.
  4. Enter the interest rate quoted to you, or use a current national average.
  5. Choose a loan term — 30 years gives the highest qualifying price; 15 years is more conservative and saves substantial interest.
  6. Adjust the property tax rate to match your county (typical U.S. range is 0.5%–2.5%).
  7. Set your max DTI. 36% is the traditional conservative cap; 43% is roughly the QM mortgage limit; lenders may push higher with strong credit.
  8. Compare results at different DTI levels. The "comfortable" affordability is usually well below the lender's maximum.

Worked examples

Comfortable vs maximum

Income $85K, $500/mo debts, $40K down, 6.5% rate, 30-year, 1.1% property tax, $1,500 insurance: At 28% housing-only DTI: max price ≈ $230,000 At 36% total DTI: max price ≈ $295,000 At 43% total DTI (FHA): max price ≈ $360,000 A 15-percentage-point increase in DTI allowance buys 56% more house — and 56% more stress when something breaks.

Impact of paying off a car

Same household, but they pay off the $500/mo car loan before applying. At 36% DTI: max price jumps from $295K to ≈ $360,000. Paying off a single car loan can add roughly $65,000 to qualifying home price. The lender doesn't care that the car is paid off in your mind — only what shows on your credit report at application.

When to use this calculator

Use this calculator at the start of a home search to set realistic expectations, and again after any major change to income, debts, or down payment. It is most useful for figuring out which homes are worth visiting; once you have a specific home in mind, switch to the mortgage payment calculator for exact PITI on that price.

This is a planning estimate, not a pre-approval. Actual lender DTI calculations may treat certain debts differently (e.g., student loans on income-based repayment plans), and a real pre-approval considers your full credit report, assets, and employment history. For an authoritative number, ask a lender for pre-approval — it's free and usually completed within a few days.

Common mistakes to avoid

  • Confusing pre-qualification with what you can afford. A lender will often qualify you for more than is wise. The lender's job is to assess default risk, not your quality of life.
  • Forgetting the costs lenders don't count. HOA fees, maintenance (commonly budgeted at 1% of home value per year), utilities, and lawn care can add hundreds per month on top of PITI.
  • Using net income instead of gross. DTI ratios use pre-tax income because that's what lenders see on tax returns.
  • Not including all debts. Lenders pull your credit report and find them anyway; don't accidentally inflate your apparent qualifying ceiling.
  • Ignoring rate sensitivity. A 1-point rate increase can drop your affordability by 10%. Get a quote, not a guess.
  • Treating the maximum as a goal. Buying at the ceiling means no margin for repairs, rate-adjustment risk, or a job loss in either income.

Frequently Asked Questions

Sources & further reading

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