Mortgage Affordability Calculator
Find out how much house you can afford based on your income, debts, and down payment. Uses the standard 28/36 rule and lender debt-to-income guidelines.
Part of our Finance Calculators collection.
Mortgage Affordability Calculator
Free online calculator
Combined household income before taxes
Car loans, student loans, credit cards (minimum payments)
How to Use This Calculator
- 1
Enter your annual household gross income.
- 2
Enter all existing monthly debt payments (car, student loans, credit card minimums).
- 3
Enter your available down payment.
- 4
Fill in the current interest rate and property tax estimate.
- 5
See the maximum home price you qualify for under standard lender guidelines.
How Affordability is Calculated
Lenders use two key ratios: 28% Rule (front-end DTI): Max housing payment = Gross monthly income × 0.28 36% Rule (back-end DTI): Max total debt = Gross monthly income × 0.36 Max housing payment = (Gross monthly income × 0.36) − existing monthly debts Actual limit = lower of the two calculations Max loan = solve mortgage formula for principal given payment
Example Calculation
Example: $90k income, $400/month debts, $60k down
Inputs
Result
Affordable home price: ~$380,000
Monthly income: $7,500. 28% rule: $2,100 max housing. 36% rule: $2,700 − $400 debts = $2,300 housing. Using $2,100 limit at 6.8% for 30 years ≈ $320k loan + $60k down = ~$380k home.