Free Mortgage Amortization Tool
Mortgage Amortization Calculator with Extra Payments
Calculate your mortgage amortization schedule and see how each payment is divided between principal and interest. Add an extra monthly principal payment to estimate how much interest you could save and how much sooner you could pay off your mortgage.
Enter your mortgage details
Estimate your monthly principal and interest payment and see how each payment is divided between principal, interest, and remaining loan balance.
Enter the mortgage principal after your down payment.
Estimate how additional monthly principal payments may shorten the mortgage and reduce interest.
Amortization Results
Enter your mortgage details
Your estimated monthly payment and amortization schedule will appear here.
How mortgage amortization works
Mortgage amortization is the process of gradually paying off a home loan through scheduled payments. With a typical fixed-rate mortgage, the required monthly principal and interest payment generally stays the same, but the amount allocated to principal and interest changes throughout the life of the loan.
During the early years of a mortgage, a larger portion of each payment usually goes toward interest because the outstanding loan balance is higher. As the balance declines, the interest portion generally becomes smaller and more of each payment goes toward principal.
Principal
Reduces your balance
The principal portion of a payment directly reduces the outstanding amount you owe on the mortgage.
Interest
Cost of borrowing
Interest is the cost charged by the lender for borrowing the money used to finance the home.
Extra Payments
Pay off faster
Additional principal payments can reduce the balance faster, potentially shortening the payoff period and lowering total interest.
What is a mortgage amortization schedule?
A mortgage amortization schedule shows how your scheduled mortgage payments are applied over time. It typically lists the payment amount, principal paid, interest paid, and remaining mortgage balance for each payment period.
Reviewing an amortization schedule can help you understand how quickly your mortgage balance declines and how much of your payment goes toward interest during different stages of the loan.
Mortgage principal vs. interest
Principal is the amount borrowed to finance the home. Interest is the cost charged by the lender for providing that financing. Together, principal and interest make up the core payment on a standard fixed-rate mortgage.
Early in the Mortgage
The outstanding balance is relatively high, so a larger portion of the scheduled payment generally goes toward interest.
Later in the Mortgage
As the balance decreases, less interest is generally charged and a larger portion of the scheduled payment goes toward principal.
Mortgage payment formula
The scheduled principal and interest payment for a standard fixed-rate mortgage can be estimated using the mortgage balance, periodic interest rate, and total number of scheduled payments.
Monthly Principal & Interest Formula
M = P × [r(1 + r)ⁿ] ÷ [(1 + r)ⁿ − 1]
M = monthly payment
P = mortgage principal
r = monthly interest rate
n = total number of monthly payments
How a 30-year mortgage amortization schedule works
A standard 30-year mortgage with monthly payments contains up to 360 scheduled payments. Because the repayment period is long, the balance decreases gradually during the early years before principal repayment becomes a larger portion of each payment.
A shorter mortgage term generally increases the required monthly payment but can substantially reduce the total amount of interest paid over the life of the loan.
Extra mortgage payment calculator
Making additional payments toward mortgage principal can reduce your outstanding balance faster. Because future interest is generally calculated using the remaining balance, reducing principal sooner can lower the amount of interest paid over the life of the mortgage.
Use the Extra Monthly Principal field above to compare your standard amortization schedule with an accelerated payment strategy. The calculator can estimate the potential interest savings and how much earlier the mortgage may be paid off.
How to pay off a mortgage early
One way to shorten a mortgage payoff period is to make additional principal payments. Even relatively small recurring extra payments can make a meaningful difference when they are made consistently over a long period.
Before making additional payments, consider your broader financial situation and verify how your mortgage servicer applies extra funds.
Check your mortgage terms first
Confirm that additional payments will be applied to principal. Review your mortgage agreement for payment-processing rules, prepayment conditions, penalties, or other lender-specific requirements.
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What is a mortgage amortization schedule?
A mortgage amortization schedule shows how scheduled payments are divided between principal and interest and how the remaining loan balance changes over time.
Why do early mortgage payments contain more interest?
Interest is generally calculated using the outstanding mortgage balance. Because the balance is highest near the beginning of the loan, the interest portion of early payments is usually larger.
Do extra mortgage payments reduce interest?
Extra payments applied directly to principal can reduce the outstanding balance faster. Depending on the mortgage terms, this can reduce total interest and shorten the payoff period.
How much can I save by making extra mortgage payments?
Potential savings depend on your mortgage balance, interest rate, remaining term, and extra payment amount. Enter an additional monthly principal payment above to estimate the difference.
How many payments are in a 30-year mortgage?
A standard 30-year mortgage paid monthly normally contains 360 scheduled monthly payments.
Does this calculator include property taxes and insurance?
No. This amortization calculator focuses on mortgage principal and interest. Use the CalcForBiz Mortgage Calculator for an estimate that can also include property taxes, homeowners insurance, PMI, and HOA fees.
Can I use this calculator for a 15-year mortgage?
Yes. Enter the appropriate mortgage term and the calculator can estimate the amortization schedule based on the values provided.
Will extra payments automatically shorten my mortgage?
They may if the lender applies the additional amount directly to principal. Check your mortgage agreement and servicer instructions because payment handling can vary.
Estimate only
This mortgage amortization calculator is provided for general informational and educational purposes only. Results are estimates and may differ from your lender's actual amortization schedule because of rounding, payment dates, fees, loan terms, escrow requirements, and other factors. This tool does not provide financial, tax, legal, or lending advice.