Home Affordability Calculator
How much house can you actually afford? The 28/36 rule, worked backwards from your income.
Lenders judge affordability with the 28/36 rule: housing costs should stay under 28% of gross monthly income, and all debts together under 36%. This calculator starts from those limits and works backwards — through the mortgage formula and your tax and insurance estimates — to the highest home price that keeps the full monthly payment inside the rule.
How to use
- Enter your annual gross income and your monthly debt payments (car, cards, student loans — minimums and regular payments).
- Add the down payment you have saved, the mortgage rate and term you expect.
- Adjust property tax and insurance to your area if you know them — defaults are US averages.
- Click "Calculate my price" for the maximum price that fits the 28/36 rule, and the payment breakdown at that price.
About this tool
Working backwards matters because tax and insurance ride on the price itself. Every extra dollar of price adds mortgage payment plus roughly another cent a year in tax — the solver above handles that loop exactly instead of guessing.
Treat the result as a ceiling, not a target. The 28/36 rule ignores childcare, savings goals and sanity. Many buyers are happier a notch below the maximum. Everything runs in your browser — your income never leaves your device.
How it works
Budgets first: front-end budget = 28% of gross monthly income; back-end budget = 36% of gross monthly income minus existing monthly debts. The housing budget is the smaller of the two. From that budget, subtract insurance and HOA to get the amount A available for principal, interest and tax.
Then solve for price P in one step: (P − down) × f + P × (tax% ÷ 12) = A, where f is the monthly mortgage factor per dollar borrowed. So P = (A + down × f) ÷ (f + tax% ÷ 12). The price feeds its own tax bill, which is why a simple division by the mortgage factor alone overstates what you can afford.
Worked examples
$95,000 income, $450/month debts, $60,000 down, 6.5% for 30 years: Gross monthly income is $7,916.67. Front-end budget: $2,216.67. Back-end: $2,850 − $450 = $2,400 — so the front-end rule binds at $2,216.67. After $200 insurance and no HOA, $2,016.67 covers principal, interest and tax, which solves to a maximum price of about $331,000 with a loan of about $271,000.
Frequently asked questions
What is the 28/36 rule?
A long-standing lender guideline: no more than 28% of gross income on housing (mortgage, tax, insurance, HOA), and no more than 36% on housing plus all other debts. Some loan programs allow higher ratios, but 28/36 remains the standard affordability benchmark.
Which of the two limits binds me?
Whichever is smaller. With low debts the 28% front-end rule usually binds; with a car loan and student loans, the 36% back-end rule often caps you first. The result tells you which one applied.
Why is the price lower than a simple "4x income" guess?
Because tax and insurance are priced in, and your existing debts eat into the 36% allowance. Rules of thumb skip both.
Does this include PMI or closing costs?
No. PMI applies when the down payment is under 20% of the price, and closing costs are one-time cash, not monthly budget. Keep both in mind on top of this ceiling.
Is my data sent anywhere?
No. Every calculation runs in your browser. Nothing you type ever leaves your device.
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