Finance calculator

Free house affordability calculator

Find out how much house you can afford — enter income, debts, and rate to see the maximum home price that fits the 28/36 rule, updated live, as you type.

InputsLive
Monthly gross income
$/mo
Monthly debt payments
$/mo
Down payment
$
Interest rate
%
Loan term
yrs
Max DTI
%
Result
Max home price
$417,732
Loan: $357,732 · Down: $60,000 · Housing: $2,380/mo
Max home price$417,732
Max loan$357,732
Max housing pmt$2,380
Down payment$60,000

Estimate based on DTI guideline only. Lenders also consider credit score, assets, employment, and other factors. Consult a licensed lender for pre-approval.

Results are estimates. Consult a professional.

How it's calculated

How the house affordability calculator works

Lenders use two debt-to-income ratios — front-end and back-end DTI — to cap how much mortgage you can carry. The calculator applies both limits simultaneously and returns the lower of the two as your maximum affordable payment. It then converts that payment into a maximum loan amount using the standard amortization formula, and adds your down payment to produce a maximum home price.

Front-end DTI cap: max housing payment ≤ 28% of gross monthly income
Back-end DTI cap: all debts ≤ 36–43% of gross monthly income
Max P&I = min(front cap, back cap other monthly debts) taxes insurance HOA
Max loan = P&I payment × (1 (1 + r)^n) / r
Max home price = max loan / (1 down payment %)

Where r is the monthly interest rate (annual rate ÷ 12) and n is total payments (term in years × 12). The front-end ratio applies only to housing costs; the back-end ratio stacks all monthly debt obligations — student loans, auto payments, credit cards — against your gross income.

Fannie Mae Selling Guide — B3-6-02 Debt-to-Income Ratios
Example

Worked example: $120k household income

Example: $120k income, $800/mo other debts, 7% rate, 20% down

The Chen family earns $120,000/year ($10,000/month) gross. They have $800/month in existing debt (car + student loans). Their lender quotes 7% on a 30-year fixed. Estimated property tax + insurance + HOA = $500/month.

Front-end cap (28%): $10,000 × 0.28 = $2,800 max housing
Back-end cap (43%): $10,000 × 0.43 $800 debts = $3,500 available for housing
Binding limit = $2,800 (front-end is lower)
Max P&I = $2,800 $500 taxes/ins/HOA = $2,300
Max loan = $2,300 × (1 (1.005833)^360) / 0.005833 ≈ $345,000
Max home = $345,000 / 0.80 = $431,250
~$430,000
With $120k income, $800/mo in debt, and a 7% rate, the Chens can afford a home up to roughly $430,000 with 20% down.
Quick reference

Max affordable home by income at 7% / 28% DTI

The table below estimates maximum home prices across household income levels. Assumptions: 7% rate, 30-year term, 20% down payment, 28% front-end DTI cap, no other debts. Add property tax and insurance before comparing to a real offer.

Annual IncomeMax Housing PaymentMax P&I (−$400 est. tax/ins)Max LoanMax Home Price
$75,000$1,750 / mo$1,350 / mo$202,000$252,000
$100,000$2,333 / mo$1,933 / mo$289,000$361,000
$150,000$3,500 / mo$3,100 / mo$464,000$580,000
$200,000$4,667 / mo$4,267 / mo$638,000$798,000

Source: CFPB, Fannie Mae DTI guidelines. Estimates only — actual qualification depends on credit score, reserves, and lender overlays.

Practical tips

Tips for maximizing what you can afford

Affordability is not a fixed number — it shifts with your rate, debts, down payment, and tax/insurance costs. Here are five levers worth pulling before you decide on a price range.

  • Pay down high-balance revolving debt first — Credit card balances factor into the back-end DTI. Eliminating a $400/month minimum payment can raise your maximum loan by roughly $60,000 at 7%.
  • Compare 15- vs. 30-year terms deliberately — A 15-year loan has a higher payment but builds equity faster and typically carries a lower rate. Run both scenarios to see which fits your cash flow.
  • Shop rates aggressively — A 0.5% rate difference on a $350k loan saves roughly $100/month and $36,000 over 30 years. Get at least three lender quotes on the same day.
  • Factor in property taxes early — Property tax rates vary from 0.3% to 2.2% of home value annually. A $500k home in a 2% tax state adds $833/month — enough to push you below the front-end DTI cap.
  • Get pre-approved, not just pre-qualified — Pre-approval involves verified income and credit documents and gives you a firm ceiling, not just an estimate. Sellers treat pre-approved buyers more seriously in competitive markets.
Accuracy & limits

Accuracy and limitations

The calculator uses published Fannie Mae and CFPB DTI guidelines, which are the most common benchmarks for conventional loans. FHA loans allow back-end DTIs up to 57% with compensating factors. VA and USDA loans use residual income rather than DTI. Your actual approval may differ based on credit score, down payment source, reserves, and lender-specific overlays.

Not financial advice — consult a real estate professional for your specific situation.

Glossary

Affordability terms defined

Debt-to-income ratio measuring housing costs (P&I + taxes + insurance + HOA) as a percentage of gross monthly income. Conventional lenders typically cap this at 28%.
Total monthly debt obligations (housing + all other debts) divided by gross monthly income. Conventional lenders generally cap this at 36–43%.
Total pre-tax income from all sources before deductions, used by lenders to calculate DTI ratios.
Principal and interest — the two core components of a mortgage payment that repay the loan itself, separate from taxes, insurance, and HOA.
Private mortgage insurance required when the down payment is less than 20%. Adds 0.5–1.5% of the loan annually to the housing cost, reducing what the DTI math allows you to borrow.
A lender's key underwriting metric comparing your monthly debt payments to your monthly gross income, expressed as a percentage.
About

About this house affordability calculator

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Questions

Frequently asked questions about the free house affordability calculator

A house affordability calculator is a free online tool that helps you calculate the maximum home price you can afford from income, debts, down payment, and rate. Limited by front-end DTI (housing < 28% of income) and back-end DTI (total debt < 36-43% of income). It runs entirely in your browser with instant results and no sign-up.
No — actual loan terms depend on credit, income docs, and lender underwriting. Use this for planning and what-if scenarios; get a real Loan Estimate before making decisions.
When the calculator asks for them. PITI calculations include property tax, insurance, and PMI; raw P&I calculations don't.
Lenders round payment amounts and may include escrow buffers. Property tax and insurance change over time. Real payments vary 1-5% from these estimates.

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