Amortization Schedule Calculator
Enter your loan amount, APR, and term to calculate your monthly payment, total interest, and total repayment. Then view the full payment-by-payment amortization table showing exactly how each payment is split between principal and interest.
Educational tool only. Results are informational estimates assuming a fixed interest rate with standard monthly amortization. Does not account for origination fees, variable rates, escrow, or prepayment. This calculator does not constitute financial advice. Consult your lender for exact figures.
Understanding Amortization
Amortization is the process of paying off a loan through equal monthly payments over a fixed term. Each payment covers the interest accrued that month on the remaining balance, plus a portion of the principal. As the balance decreases, the interest component shrinks and the principal component grows — even though the payment amount stays the same.
This is why paying even a small extra amount each month can have a dramatic effect on total interest paid. Extra principal payments reduce the balance on which future interest is calculated.
Monthly Payment Formula
M = P × [r(1+r)^n] / [(1+r)^n - 1] Where: M = monthly payment P = loan principal r = monthly rate = APR ÷ 12 n = total payments = years × 12 Each month: Interest = remaining balance × r Principal = M − interest New balance = old balance − principal Example: $200,000 at 7% for 30 years Monthly payment ≈ $1,331 Payment 1: $233 principal / $1,167 interest Payment 180: $537 principal / $794 interest Payment 360: $1,323 principal / $8 interest Total interest ≈ $279,022
FAQ
What is an amortization schedule?
An amortization schedule is a complete table showing every loan payment — the amount going to principal, the amount going to interest, and the remaining balance after each payment. It shows precisely how a loan is paid off over its lifetime.
Why does most of my early mortgage payment go to interest?
Interest is charged on the remaining balance each month. At the start of a loan, the balance is at its highest, so interest is also at its highest. As you pay down principal over time, less interest accrues and more of each fixed payment reduces the balance. By the final payments, almost the entire payment is principal.
How much interest can I save by paying extra each month?
Significantly. On a $200,000 mortgage at 7% for 30 years: adding $100/month extra saves approximately $29,000 in total interest and cuts about 4 years off the loan. Adding $200/month saves about $50,000 and cuts about 7 years. Use the calculator to see the baseline, then subtract to estimate savings from extra payments.
Want the full explanation? Read the Amortization Schedule Guide →