What This Mortgage Affordability Calculator Does
This calculator quickly estimates the home price you can afford based on your income, debts, down payment, interest rate, and local property tax. It also gives you expected monthly payments for principal, taxes, and major costs.
How to Use
- Enter your annual income (before taxes).
- Provide your down payment (amount you plan to put down).
- Enter your monthly debt payments (credit cards, loans, car, etc.).
- Set the interest rate (use your lender’s quote or today’s rate).
- Select loan term (30 years is most common).
- Enter an estimated property tax rate (U.S. average is ~1.1%).
- Click Calculate to see your max home price and payment summary.
Example:
Annual income: $95,000, down payment: $40,000, debts: $350/month, rate: 6.5%, term: 30 years, prop. tax: 1.1% ⇒ $403,108 max affordable price (~$2,677/month payment).
Assumptions & Formula
- Uses both the 28% "front-end" and 36% "back-end" debt-to-income (DTI) rule: mortgage payment must not exceed 28% of gross income, total debt payments ≤ 36%.
- Monthly payment includes principal + interest + property taxes. (Insurance/HOA not included; add them for full estimate!)
- You can afford the lesser of: Income-based limit or Loan-based limit.
- Mortgage payment formula: P = L × [r(1 + r)^n] / [(1 + r)^n – 1], where L = loan amount, r = monthly rate, n = number of payments.
Common Mistakes & Validation Notes
- Do not include non-housing expenses (utility bills, groceries, etc.) in "Monthly Debt".
- Rates above 10% or below 2% may yield unrealistic results—check with your lender.
- Check your actual property tax rate before assuming 1.1%. High-tax states/UI localities may differ.
- If your down payment is under 20%, lenders may require mortgage insurance (not included here).
FAQ
- How accurate is this mortgage affordability calculator?
- It offers a practical estimate based on income and standard DTI rules, but doesn’t account for everything (like insurance, HOA, or your specific lender requirements).
- What if my debt payments are high?
- Large monthly debts will lower your home price ceiling due to loan qualification rules (36% back-end DTI).
- What is a good property tax estimate?
- National U.S. average is about 1.1%, but your local rate may be much higher or lower.
- Why does down payment matter?
- It affects your total loan and thus the purchase price you can afford—larger down payment means more buying power and may avoid mortgage insurance.
- Is this calculator only for first-time buyers?
- No! Anyone can use it to explore home affordability for purchase or refinances.