Amortization Calculator
Estimate a fixed loan payment and see how the balance, interest, and principal change year by year.
How this amortization calculator helps
An amortization schedule shows how each fixed loan payment is split between interest and principal. This is useful for mortgages, car loans, student loans, and other installment loans because the interest share is usually highest near the beginning.
What the yearly table means
The table groups the monthly payment schedule by loan year. Ending balance is the loan amount still unpaid at the end of that year. Interest is the interest paid during that year. The accumulative columns show running totals from the start of the loan through that year.
Payment formula
For a fixed-rate loan, the standard monthly payment is:
M = P x r(1 + r)^n / ((1 + r)^n - 1)
Where P is the loan amount, r is the monthly interest rate, and n is the number of monthly payments. If the annual interest rate is 0%, the payment is simply the loan amount divided by the number of months.
Extra principal payments
Extra monthly principal payments reduce the balance faster. Because future interest is calculated from the remaining balance, even a small extra amount can shorten the payoff time and lower total interest.
Optional loan start date
If you enter a loan start date, the schedule includes a payment date column. Dates are written with month abbreviations, such as Jun 1, 2030, to avoid numeric date-format confusion.