Mortgage Amortization Calculator — Free Payment & Schedule Tool
Calculate your monthly mortgage payment, total interest, and see your full amortization schedule. 100% client-side — your loan details stay in your browser. No data collection, no tracking, complete privacy.
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How Mortgage Amortization Works
Amortization is the process of paying down a loan through regular monthly payments. Each payment covers two parts: interest (the cost of borrowing) and principal (your loan balance). Early in the loan, most of your payment goes to interest. As time passes, a larger share goes toward principal until the loan is fully paid. An amortization schedule shows exactly how each payment is split between principal and interest, your remaining balance, and how much total interest you'll pay.
Worked Example
A $400,000 mortgage at 6.75% interest over 30 years:
- Monthly P&I payment: $2,594.34
- Total interest paid: $533,840.66
- Total amount paid: $933,840.66
By paying an extra $300/month, you'd pay off the loan in ~24 years and save over $100,000 in interest. Use the calculator above to model your own scenario.
Frequently Asked Questions
What is PMI and do I need it?
Private Mortgage Insurance (PMI) is required if your down payment is less than 20% of the home's purchase price. PMI protects the lender if you default. Typical costs are 0.5% to 1% of the loan amount annually, added to your monthly payment. You can usually remove PMI once you've built 20% equity in your home.
What's the difference between escrow and insurance?
Your mortgage payment typically includes Principal & Interest (P&I), property taxes, homeowners insurance, and sometimes PMI—often called PITI. Escrow is a separate account where your lender holds tax and insurance payments, then pays them on your behalf when due. This calculator shows P&I only; add estimated property tax and insurance to get your true monthly cost.
Should I pay biweekly or monthly?
Biweekly payments (26 per year) result in one extra payment per year compared to monthly (12), paying off your loan faster and saving interest. However, not all lenders support biweekly payments, and there may be fees. For a $400k mortgage at 6.75%, biweekly saves roughly $40,000 in interest over 30 years.
How much can I save by paying extra?
Paying extra principal reduces both the loan balance and total interest paid while shortening your payoff date. For example, adding $200/month to a $400k loan at 6.75% over 30 years can save you $80,000+ in interest and pay off the loan 10 years early. Use the "Extra Monthly Payment" field in the calculator to see your savings.
What does amortization mean?
Amortization is the process of paying down a debt over time through regular payments. Each payment covers interest (cost of borrowing) and principal (reducing the loan balance). Early payments are mostly interest; later payments are mostly principal. An amortization schedule shows exactly how much of each payment goes to each.