Amortization calculator.
Estimate monthly payments, total interest, payoff timing, extra-payment savings, and detailed amortization schedules.
Use the Amortization Calculator.
Enter a loan amount, APR, term, start date, and optional extra payments to see monthly payment, total interest, payoff date, balance charts, and full annual and monthly schedules.
Loan details
Set the original loan terms, then add optional monthly, yearly, or one-time extra payments to compare how quickly the balance is paid down.
Loan
Core loan values used to calculate the fixed monthly payment.
Start date
Used to label monthly and yearly amortization schedules.
Extra payments
Optional extra payments to compare payoff time and interest savings.
More one-time payments
Add extra one-time principal payments for specific months and years, useful for bonuses, tax refunds, or planned lump-sum payments.
Example calculations
Click an example to apply the values to the calculator, then review the payment, interest, charts, and amortization schedule.
Personal loan
Loan: $100,000 at 6% APR for 3 years.
Monthly payment: about $3,042.19Mortgage-style loan
Loan: $250,000 at 6.5% APR for 30 years.
Monthly payment: about $1,580.17Extra payment example
Loan: $100,000 at 6% APR for 3 years with $100 extra monthly.
Pays off about 1 month early and saves about $330 interest.Where your money goes
Principal, interest, and extra payments over the life of the loan.
Balance over time
Remaining loan balance by year.
Yearly principal and interest
How each year’s payments split between interest and principal.
Annual amortization schedule
Year-by-year interest, principal, extra payments, and ending balance.
Monthly amortization schedule
Month-by-month payment detail with interest, principal, extra payments, and ending balance.
About the Amortization Calculator
This amortization calculator shows how a loan is paid off over time. Enter the loan amount, interest rate, and term, and it returns the monthly payment, the total interest you will pay, the full payoff cost, and a chart of your falling balance year by year. Add an optional extra monthly payment to see how much interest and time you save. It works for mortgages, auto loans, student loans, and personal loans.
What amortization means
Amortization is the process of paying off a loan with equal periodic payments. Early payments are mostly interest; later payments are mostly principal. The payment is found with M = P · r / (1 − (1 + r)−n), and each month the interest portion equals the current balance × the monthly rate, with the rest reducing the principal.
Worked example
A $250,000 loan at 6.5% over 30 years has a monthly payment of about $1,580 and costs roughly $318,861 in interest — more than the amount borrowed. Adding even a small extra monthly payment shortens the term and cuts that interest noticeably, because every extra dollar goes straight to principal.
How extra payments help
Because interest is charged on the remaining balance, paying extra early has the biggest effect. The calculator recomputes the payoff month-by-month, so the "interest saved" figure reflects exactly how your extra payment shortens the loan and lowers lifetime interest.
Related calculators
Mortgage Calculator · Loan Calculator · Compound Interest Calculator
FAQ
Quick answers about amortization, payment schedules, interest, principal, and extra-payment savings.
What does an amortization calculator do?
It breaks a fixed-rate loan into scheduled payments and shows how much goes to interest, how much reduces principal, the ending balance, total interest, and payoff time.
What inputs do I need?
Enter the loan amount, loan term in years and months, interest rate, and loan start date. You can also add extra monthly, yearly, or one-time payments to compare payoff savings.
What is an amortization schedule?
An amortization schedule is a table showing each payment period with interest paid, principal paid, and the remaining loan balance after that payment.
Why is so much of my early payment interest?
Interest is calculated on the current balance. Since the balance is highest at the start, early payments include more interest. As the balance falls, more of each payment goes toward principal.
What is the difference between principal and interest?
Principal is the amount borrowed or the remaining balance. Interest is the cost charged by the lender for borrowing that money.
How do extra payments change the result?
Extra payments reduce the principal directly. Lower principal means less future interest, so extra payments can shorten the payoff time and reduce total interest.
Can I use it for a mortgage, auto loan, or personal loan?
Yes. It works for common fixed-rate amortizing loans, including mortgages, auto loans, student loans, business loans, and personal loans.