Mortgage Affordability Calculator
Find out how much house you can afford.
All calculations happen locally in your browser — nothing is uploaded, stored or tracked.
Enter your income
Annual gross income.
Add monthly debts
Car, credit cards, student loans, other payments.
Set rate, term, down payment
Plus your local tax/insurance estimates.
What Is a Mortgage Affordability Calculator?
A mortgage affordability calculator works backwards: instead of payment from price, it finds the maximum home price consistent with your income and debts. Lenders use debt-to-income (DTI) ratios — the back-end ratio (total debt payments ÷ gross income) typically capped at 36–43% for conventional loans.
The calculator uses the back-end DTI limit you choose, subtracts your existing monthly debts, and finds the mortgage payment, loan amount and home price that fit. All figures are your inputs.
The Method
The home price is the loan amount plus your down payment. Property tax and insurance are subtracted from the allowed payment first, since they are part of the housing cost.
Assumptions
Your data never leaves your device.
Every calculation on this site runs in your browser using vanilla JavaScript. Nothing is uploaded, stored or tracked.
- 100% local, client-side calculations
- No data stored on any server
- No tracking, no analytics, no ads scripts
- Works offline once loaded
Frequently Asked Questions
How much house can I afford?
A common rule is a home price of 2.5–3× your gross annual income, refined by the DTI test this calculator applies.
What is the 28/36 rule?
Lenders often cap housing costs at 28% of gross income and total debts at 36%. Many programs allow 43% for the total.
What is DTI and why does it matter?
Debt-to-income is your monthly debt payments divided by gross income — the key number lenders check.
Does the down payment affect affordability?
Yes — a larger down payment both reduces the loan and can eliminate PMI, increasing what you can afford.
Is this a pre-approval?
No. A lender's decision depends on your full financial picture, credit score and the property appraisal.