Mortgage Affordability Calculator (How Much House)
Max home price and monthly payment from income and DTI limits.
Use via API
Maximum home price you can afford from income, debts, down payment and mortgage rate, using front-end and back-end debt-to-income (DTI) limits including property tax, insurance and HOA. Send JSON, get JSON back.
POST https://pithlab.com/api/v1/tools/mortgage-affordability-calculator
curl https://pithlab.com/api/v1/tools/mortgage-affordability-calculator \
-H "Authorization: Bearer $PITHLAB_KEY" \
-H "Content-Type: application/json" \
-d '{"income":90000,"debts":400,"downPayment":40000,"rate":6.5,"termYears":30,"taxPercent":1.1,"insurance":1500,"hoa":0}'About the Mortgage Affordability Calculator
Estimate how much house you can afford from your income, debts and down payment, using front-end and back-end DTI limits, with tax, insurance and HOA included.
How to use the Mortgage Affordability Calculator
- Enter your gross annual income, your other monthly debt payments and your down payment.
- Enter the mortgage rate and term, plus property tax, insurance and any HOA fee. Adjust the DTI limits if your lender uses different ones.
- Read the maximum home price and monthly housing payment, and see which limit is holding you back.
Examples
Input
90000, 400/month debts, 40000 down, 6.5%, 30 years, 1.1% tax, 1,500 insurance, 28/36
Output
Max home price 307,823.74 (loan 267,823.74, 13% down). Max housing payment 2,100.00 a month: principal and interest 1,692.83, tax 282.17, insurance 125.00, HOA 0.00
Input
120000, 1200/month debts, 60000 down, 7%, 30 years, 1.2% tax, 1,800 insurance, 150 HOA, 28/36
Output
Max home price 326,561.26 (loan 266,561.26, 18.4% down). Max housing payment 2,400.00 a month: principal and interest 1,773.44, tax 326.56, insurance 150.00, HOA 150.00
Frequently asked questions
What are front-end and back-end DTI?
Debt-to-income ratios compare monthly payments with gross monthly income. Front-end counts only housing (mortgage, property tax, insurance, HOA); back-end adds your other debts. The classic 28/36 rule caps them at 28% and 36%. The tighter of the two sets your budget.
How is the maximum price worked out?
Housing cost at a price P is (P − down payment) × the mortgage payment factor + P × tax rate ÷ 12 + insurance ÷ 12 + HOA. The calculator sets that equal to your allowed housing payment and solves for P.
Is this what a lender will approve?
No. It's an estimate, not lending advice. Lenders also look at credit score, savings, employment, loan type and mortgage insurance, and many allow higher ratios. Get a pre-approval for a real figure, and remember you can afford a payment doesn't mean you should stretch to it.
Does this include mortgage insurance or closing costs?
No. With a small down payment you may pay mortgage insurance (PMI), and closing costs come out of your cash. Both reduce what you can afford, so leave some margin.