What the Amortization Schedule Calculator does
This amortization schedule calculator builds the full repayment table for a loan - every payment split into interest and principal with the balance left after it - and shows exactly how much interest and how many months extra payments save. Add a regular monthly overpayment, a yearly lump sum or one-off prepayments, and the original plan and the faster plan are compared side by side.
View the schedule year by year or month by month, chart the balance, download it as a CSV for a spreadsheet, or print it. It works for mortgages, home loans, car loans and personal loans in any currency, and it all runs in your browser - nothing you enter is sent anywhere.
How to use it
- Enter the loan amount, the yearly interest rate and the term in years or months. Add the month of your first payment if you want real dates in the table.
- Add any extra payments: a fixed amount every month (from a payment number you choose), a lump sum once a year, or one-off payments in specific months under "One-off payments".
- Read the headline: with extras it is the interest saved and how much sooner the loan ends; without extras it is the monthly payment.
- Compare the original plan with the extra-payment plan in the table, and switch between the yearly roll-up and the month-by-month schedule.
- Download the schedule as CSV to open in Excel or Google Sheets, or print it.
Reading the results
Early payments are mostly interest. On a 30-year loan the first payment can be over 80% interest, because interest is charged on the whole balance; as the balance falls, more of each payment goes to principal. The yearly table makes this visible.
Every extra paid goes straight to principal, so it stops interest being charged on that amount for the rest of the loan. That is why small extras early in a long loan save far more than the same extras near the end.
Here the regular payment stays the same and the loan finishes sooner. Some lenders can instead keep the end date and lower your payment (a recast or re-amortization); that saves less interest, and you would need to ask your lender for it.
Worked example: a 200,000 mortgage at 6% over 30 years, with 100 extra a month
The monthly payment is 200,000 x 0.005 / (1 - 1.005^-360) = 1,199.10. In month one, interest is 200,000 x 6% / 12 = 1,000.00, so only 199.10 reduces the balance, leaving 199,800.90.
Over 360 payments the loan costs about 231,677 in interest (the figure with every month rounded to the cent).
Paying 100 extra every month from the start, the first month repays 299.10 of principal instead of 199.10. The loan is cleared after 295 payments - 24 years and 7 months instead of 30 years - and total interest falls to about 182,538. The extra 29,400 paid in saves about 49,139 of interest and 65 payments.
Formulas and scoring rules
- Monthly payment
payment = P x i / (1 - (1 + i)^-n), i = annual rate / 12Rounded to the cent. A 0% loan is P / n.- Interest each month
interest = balance x annual rate / 12Rounded to the cent, half away from zero, as lenders' statements are.- Principal each month
principal = payment - interest + extra payment (never more than the balance)- New balance
balance = previous balance - principalThe final payment is whatever clears the remaining balance, so it can differ from the others by a few cents.- Savings
interest saved = interest without extras - interest with extras; months saved = payments without extras - payments with extras
How this differs from the Loan EMI and Mortgage calculators
The Loan EMI Calculator and the Mortgage Calculator give the monthly payment and a basic schedule. This page is about paying a loan off faster: one-off, monthly and yearly extra payments, the interest and months they save compared with the original plan, a yearly roll-up and a schedule to export or print.
Before you make extra payments
Check whether your loan has a prepayment charge. Many fixed-rate mortgages in the UK charge an early repayment charge above a yearly overpayment allowance, often 10% of the balance. In India the Reserve Bank has barred foreclosure and prepayment charges on floating-rate loans to individuals for non-business purposes, but fixed-rate loans can still carry them. In the United States, Regulation Z limits prepayment penalties on most residential mortgages.
Tell the lender that an overpayment is for principal. Some lenders treat extra money as an early payment of the next instalment unless you say otherwise, which does not save interest in the same way.
Limitations: what the result does not prove
- It assumes a fixed rate for the whole term and payments exactly one month apart. Variable-rate loans, interest-only periods and payment holidays change the schedule.
- Lenders calculate daily interest, round differently or charge fees, so a real statement can differ from this schedule by small amounts.
- It does not include prepayment or early repayment charges, insurance, taxes or escrow; add those separately when deciding whether overpaying is worth it.
- Whether paying a loan off early is wise depends on your savings, other debts and tax position - this shows the arithmetic, not advice.
Privacy: where your data goes
Everything you paste, type or drop is processed in this browser tab. It is not uploaded, logged, stored or sent to analytics. Session recording and tag-manager scripts are switched off on this page.
Standards and sources
- CFPB - What is amortization and how could it affect my auto loan?
- Reserve Bank of India - Levy of foreclosure charges / pre-payment penalty on floating rate term loans
- 12 CFR 1026.43(g) (Regulation Z) - Prepayment penalties on residential mortgages
Frequently asked questions
How much interest will I save by paying extra on my loan each month?
Enter the loan and the extra amount: the headline shows the interest saved and how much sooner it ends. On a 200,000 loan at 6% over 30 years, 100 extra a month saves about 49,139 of interest and ends the loan 5 years and 5 months early.
Is it better to make one large prepayment or extra monthly payments?
The earlier money reaches the principal, the more interest it saves, so a lump sum now beats the same total spread over later years. Add both to the calculator - a one-off in an early month against a monthly extra - and compare the savings.
Why is most of my early mortgage payment interest?
Interest is charged on the outstanding balance, which is largest at the start. On 200,000 at 6%, the first month's interest is 1,000 of a 1,199.10 payment; only 199.10 repays the loan. The share going to principal grows every month.
How do I make an amortization schedule in Excel?
Download the CSV here and open it in Excel or Google Sheets - every month's payment, extra, interest, principal and balance is in its own column. To build one yourself, use PMT for the payment and, each row, interest = balance x rate / 12.
Do extra payments reduce my EMI or my loan term?
Usually the term: the instalment stays the same and the loan ends sooner, which is what this calculator shows and what saves the most interest. Some lenders will lower the instalment instead if you ask; that keeps the end date and saves less.
What does an annual prepayment do to a home loan?
Use "Extra once a year": it is paid with every 12th instalment. A yearly 1,00,000 prepayment on a 50 lakh home loan at 8.5% over 20 years cuts years off the loan; the comparison table shows exactly how many and the interest saved.
Can I see the schedule with real dates?
Yes. Enter the month of your first payment and every row is labelled with its month and year, the yearly roll-up shows each year's months, and the headline gives the month you will be debt-free.
Last reviewed by the A2Z.Tools team against the sources listed above.
