Amortization Calculator
Calculate a full loan amortization schedule. See exactly how each payment splits between principal and interest, and watch your balance decrease month by month.
Part of our Finance Calculators collection.
Amortization Calculator
Free online calculator
$
%
$
Additional principal payment each month
How to Use This Calculator
- 1
Enter loan amount, interest rate, and term.
- 2
Optionally add extra monthly payments to see accelerated payoff.
- 3
See your monthly payment and summary.
- 4
The full schedule shows principal/interest split for every payment.
How Amortization Works
Monthly Payment = P Ć [r(1+r)^n] / [(1+r)^nā1] Each month: Interest Portion = Remaining Balance Ć Monthly Rate Principal Portion = Payment ā Interest Portion New Balance = Remaining Balance ā Principal Portion Early payments are mostly interest; later payments are mostly principal.
Example Calculation
Example: $25,000 at 8.5% for 60 months
Inputs
loanAmount: 25000annualRate: 8.5loanTermMonths: 60
Result
$513/month | $5,779 total interest
Month 1: $177 interest, $336 principal. Month 60: $4 interest, $510 principal ā shows how the split shifts over time.
Frequently Asked Questions
Why do early payments go mostly to interest?
Your interest is calculated on the outstanding balance. Early on, the balance is highest, so interest is highest. As the balance falls, less of each payment goes to interest and more reduces principal.
How much does an extra $100/month save?
On our $25,000 example, an extra $100/month saves ~$1,200 in interest and cuts the loan term by about 10 months.