Mortgage Affordability Calculator

Find the home price your income comfortably supports, based on a healthy debt-to-income ratio.

Gross annual income

Monthly debt payments

Down payment

Interest rate

Term

Based on a conservative 36% back-end debt-to-income ratio.

Home price you can afford

Max monthly payment

Supported loan amount

Your down payment

Excludes taxes/insurance — a ceiling, not a recommendation.

How to Use

1. Enter your gross annual income and total monthly debt payments.
2. Add your available down payment.
3. Set an interest rate and loan term.
4. We show the maximum home price and loan that keep you within a healthy DTI.

Calculation Method

Maximum monthly housing payment = (gross monthly income × DTI target) − existing monthly debts. We then invert the mortgage formula to find the loan principal that produces that payment, and add your down payment to get an affordable home price. A 36% back-end DTI is used as a conservative default.

Data sources: Conventional debt-to-income guidelines (commonly a 36% back-end DTI target).

Examples

$90,000 income, $400 debts, $60,000 down

At 6.5% / 30yr this supports roughly a $330,000–$360,000 home, depending on taxes and insurance.

Frequently Asked Questions

Debt-to-income ratio is your monthly debt payments divided by your gross monthly income. Lenders use it to gauge how much you can borrow.

Many lenders prefer a back-end DTI at or below 36%, though some programs allow higher. We use 36% as a safe default.

Not necessarily. The maximum is a ceiling, not a recommendation. Leave room for savings and unexpected costs.

Related Calculators

Mortgage Payment Calculator Down Payment Calculator PMI Calculator Rent vs Buy Calculator Closing Cost Calculator

Mortgage Information Disclaimer

The mortgage calculations on this site are estimates based on the information you provide. Actual mortgage terms, interest rates, and payments will vary based on your credit score and history, debt-to-income ratio, property type and location, loan program, lender-specific requirements, and market conditions.

SmartMortgageCalcs does not provide mortgage, financial, or legal advice. We are not a mortgage lender or broker. We strongly recommend consulting with multiple licensed mortgage lenders, working with a qualified real estate agent, reviewing all documents carefully before signing, and seeking advice from a financial advisor. Our estimates do not constitute a loan offer or commitment — final loan terms are determined by the lender. Interest rates and fees shown are illustrative only.

Last updated: May 19, 2026