Amortization Schedule
| Month | Payment | Principal | Interest | Balance |
|---|
About this tool
Loan Payment Calculator
Loan Calculator works out the monthly payment, the total interest, and a full amortization schedule for any fixed-rate loan. It also handles extra monthly payments, and shows how much interest and time they actually save. The schedule exports to CSV.
How to use it
- Enter the loan amount, annual interest rate, and term in years.
- Add an extra monthly payment if you plan to overpay. Leave it at zero if not.
- Read the monthly payment, total interest and total cost.
- Scroll the amortization schedule, or use Export CSV to open it in a spreadsheet.
The amortization formula
The monthly payment comes from M = P x r x (1 + r)^n / ((1 + r)^n - 1), where P is the amount borrowed, r is the monthly rate (annual rate divided by 12) and n is the total number of payments.
Every payment is split between interest and principal. Interest is charged on the balance that is still outstanding, so early payments are mostly interest and later ones are mostly principal. That is why an extra payment made in year one saves far more than the same payment made in year four.
Worked example
Using the values the calculator loads with:
- Loan amount$25,000
- Annual rate6.5%
- Term5 years (60 payments)
Result: About $489 a month, roughly $29,345 paid in total, of which about $4,345 is interest.
When it helps
- Comparing car loan offers where the rate and term both differ.
- Seeing what an extra $50 a month actually saves over the life of a loan.
- Checking a lender's quoted payment against an independent calculation.
- Deciding between a shorter term with higher payments and a longer one with more total interest.
Common mistakes
- Comparing loans on monthly payment alone. A longer term always looks cheaper monthly and usually costs far more overall.
- Confusing the interest rate with the APR. APR folds in fees, so it is the fairer number for comparing offers.
- Assuming overpayments always reduce the term. Some lenders apply them to the next payment instead of the principal unless you specify.
