The Mortgage Calculator estimates monthly principal-and-interest payments, property-tax and insurance portions, HOA fees, total interest, total cost, and a yearly amortization schedule from home price, down payment, term, and rate assumptions.
Formula
The loan amount is home price minus down payment. For a non-zero monthly rate:
where P is the loan amount, r is the annual interest rate divided by 12, and n is the term in months. At zero interest, the payment is principal divided by months.
Property tax and home insurance are divided by 12, then HOA fees are added to form the displayed total monthly payment.
Worked example
For a 80,000 down, a 30-year term, and 6% annual interest:
- Loan amount:
$400,000 - $80,000 = $320,000. - Monthly rate:
6% / 12 = 0.5%. - The amortization formula produces a principal-and-interest payment of about $1,919 per month before taxes, insurance, and HOA fees.
Questions
Does the payment include taxes and insurance?
Yes, when you enter annual property tax and annual home insurance. They are shown separately and included in total monthly payment.
Does this include PMI or mortgage insurance?
No. PMI, lender fees, closing costs, and prepaid escrow are outside this module.
What does the amortization schedule show?
It groups each year's principal, interest, cumulative interest, and closing balance so you can see how the loan declines over time.
Limitations
The result is a mathematical estimate. Actual lender payments can include PMI, escrow changes, rate adjustments, fees, taxes, insurance changes, and payment timing differences.