Amortization Calculator
Generate a full amortization schedule showing every payment's principal, interest and remaining balance.
About the Amortization Calculator
Enter the loan amount, rate and term. The calculator gives the monthly payment, total interest and a month-by-month schedule of how much of each payment is interest, how much reduces the balance, and what's left.
Each month's interest is the balance × monthly rate; the rest of the payment reduces the balance. The schedule shows exactly how much you owe after any payment, useful for planning a sale, overpayment or refinance.
The formula
Interest = balance × i; principal = payment − interest
- i
- monthly rate: yearly rate ÷ 12
Worked example
200,000 at 6.5% over 30 years
- Payment: 1,264.14 a month
- Month 1: interest 200,000 × 0.065 ÷ 12 = 1,083.33; principal 180.81
- Over 30 years: 255,089 of interest, 455,089 in total
Questions people ask
Why does the principal portion grow?
As the balance falls, less of each fixed payment is needed for interest.
Does this match my lender?
Closely; lenders may round each month or use daily interest.
When is half the loan repaid?
Much later than halfway through the term on long loans; find the month where the balance drops below half in the schedule.