Loan Amortization Schedule
Build a full loan amortization schedule with extra and one-time payments, see interest saved, and download it as an Excel workbook with live formulas.
Enter the loan details to build the full amortization schedule.
How the Loan Amortization Schedule helps
A repayment figure alone hides how slowly the balance falls in the early years. The schedule shows every payment split into interest and principal, the balance after each one, and a yearly summary. Add a recurring extra payment or a one-time lump sum and you see exactly how much interest you save and how many payments disappear.
Method
The scheduled payment is the standard annuity payment, rounded to cents: P × r ÷ (1 − (1 + r)^−n), where r is the annual rate divided by payments per year and n is the term × payments per year, rounded to a whole number of payments. Interest each period is the opening balance × r, rounded to cents. Extra payments go straight to principal and never exceed the remaining balance; the final payment clears whatever is left.
Excel download
The .xlsx file is a working model, not a static export: the number of payments is =ROUND(term × payments per year, 0), the payment uses =PMT() on that number, every row's interest, principal and balance are formulas, and the inputs sit at the top of the sheet. Change the rate or extra payment in Excel and the whole schedule recalculates.
Example
A 250,000 loan at 5.5% over 25 years costs 1,535.22 a month and about 210,600 in interest. Paying 200 extra every month from the first payment saves about 50,800 of interest and clears the loan more than five years earlier.
Frequently asked questions
Does this match my bank's schedule?
It follows the standard method most lenders use for fixed-rate loans. Lenders may round differently, charge fees, use daily interest or change the rate, so small differences are normal.
How do extra payments reduce interest?
Every extra amount lowers the balance immediately, so each later interest charge is calculated on a smaller balance. The earlier the extra payment, the larger the saving.
Can I open the schedule in Google Sheets?
Yes. Upload the .xlsx file to Google Drive and open it with Google Sheets; the formulas are standard and recalculate there too.
For fixed-rate loans with level payments. Variable rates, interest-only periods, fees and daily interest are not modelled. Confirm figures with your lender before making financial decisions.