Loan Amortization Calculator
Full payment-by-payment breakdown for any loan.
Amortization tables render right in your browser — nothing is sent anywhereYour payment breakdown appears here
Fill in the loan details and press Calculate — the monthly payment, total interest and schedule will render right on this page, with nothing sent to any server.
How to use
Amortization is the schedule that shows exactly how each payment splits between interest and principal. Early payments are mostly interest; later payments are mostly principal. This calculator prints the monthly split for the first year and the totals for the whole term.
How to use
- Enter the loan amount, APR and term in years.
- Press Calculate to see the payment, the totals, and the first-year table.
- Read the table: the Interest column shrinks each month as the balance falls.
Example
Borrow $20,000 at 6.5% for 5 years: the payment is about $391. In month one, $108 of that goes to interest and $283 to principal. By month twelve the split is about $91 interest and $300 principal — the balance has dropped by roughly $3,600 in the first year alone.
Formula
Each period: interest = balance × monthly rate and principal = payment − interest. The balance then falls by that principal, so next month's interest is slightly smaller.
Car loans: short schedules
Car loans run 3-6 years, so the table stays readable month by month. Because the term is short, a large share of every payment goes to principal from the start — that is why car loans build equity quickly.
Student loans: long schedules
Student loans often run 10-30 years. In the first years of a 20-year loan, most of each payment is interest. A $25,000 student loan at 4.5% for 20 years costs about $13,000 in interest alone — about half the original amount. Paying extra early has an outsized effect on long loans.
Why the split shifts
The monthly rate never changes, but the balance shrinks, so the dollar amount of interest falls each month. That freed-up money goes to principal, accelerating the payoff in the back half of the loan.
FAQ
Why do early payments feel slow?
The balance is largest at first, so interest takes the bigger share of each early payment.
Can I see the full schedule?
The preview shows the first 12 months; the math covers the whole term with the same rule.
What is different for a student loan?
Only the length. A 10-30 year term means interest dominates for years — see the student section above.
How do I find the car loan version?
This page covers all loans. The car-specific entry points land here via the links from the car pages.
Reviewed by the LoanMath editorial team