Mortgage Calculator — Monthly Payment, Amortization & Total Cost
Calculate your complete monthly mortgage payment including principal and interest, property taxes, home insurance, PMI, and HOA fees. See how much total interest you pay over the life of the loan and find out how much extra payments save. Free, instant, no account required.
100% private. All calculations run locally in your browser. No data is collected or transmitted.
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How to Use the Mortgage Calculator
- 01
Enter loan details
Input home price, down payment, interest rate, and loan term. The down payment field accepts both dollar amounts and percentages.
- 02
Add optional costs
Expand the "Additional costs" section to include property tax, home insurance, HOA fees. PMI is calculated automatically if down payment is under 20%.
- 03
Review full breakdown
See monthly payment, total interest, payoff date, and the full year-by-year amortization schedule. Use the extra payment tool to see how prepayment saves interest.
Frequently Asked Questions
How is the monthly mortgage payment calculated?
The monthly principal and interest payment uses the standard amortization formula: M = P × [r(1+r)^n] / [(1+r)^n − 1], where P is the loan amount, r is the monthly interest rate (annual rate ÷ 12), and n is the total number of payments. The total monthly payment also includes property tax, home insurance, PMI (if applicable), and HOA fees.
What is PMI and when can I remove it?
PMI (Private Mortgage Insurance) is required when your down payment is less than 20% of the home price. It typically costs 0.5–1% of the loan amount per year. You can request removal once your loan-to-value ratio reaches 80% (20% equity), which happens automatically at 78% LTV under the Homeowners Protection Act.
How much does a 0.5% lower interest rate save?
On a $400,000, 30-year mortgage, reducing the rate from 7% to 6.5% saves roughly $130/month and over $46,000 in total interest over the life of the loan. Use the amortization table to see the exact difference for your specific scenario.
Should I choose a 15-year or 30-year mortgage?
A 15-year mortgage has higher monthly payments but you pay roughly half the total interest of a 30-year loan. A 30-year mortgage has lower monthly payments, giving more cash flow flexibility. On a $320,000 loan at 6.5%, the 15-year payment is about $2,790/month vs $2,023 for 30 years — but you save over $160,000 in interest.
What does extra payment do to my mortgage?
Extra payments go directly to reducing your principal balance. Because interest is calculated on the remaining balance, a lower balance means less interest accrues each month. Even $100 extra per month on a 30-year $300,000 mortgage at 6.5% saves over $45,000 in interest and cuts 4+ years off the loan term.
What is an amortization schedule?
An amortization schedule shows how each payment is split between principal and interest over the life of the loan. In early years, most of your payment goes to interest. Over time, the split shifts toward principal. By the final year, almost all of each payment reduces the principal.