Amortization Schedule Calculator

Loan amortization is the process of paying off a loan through regular payments over time. Each payment covers both principal and interest, with the proportion of principal increasing over time. It ensures the loan is completely paid off by the end of the specified term.

An amortization schedule shows each payment broken down into principal and interest components, along with the remaining balance. Interest is calculated on the outstanding balance at the beginning of each period. As you make payments, the interest portion decreases and the principal portion increases, while the total payment remains fixed.

Interest decreases because it's calculated as a percentage of the outstanding loan balance. As you pay down the principal, the balance decreases, so the interest portion of each payment becomes smaller. For example, on a $300,000 mortgage, first-month interest might be $1,750, but by month 200 it could be $200.

Yes — this calculator supports an extra payment amount applied on top of your regular payment. Paying extra principal reduces total interest charges and shortens the loan term. Check your loan agreement for prepayment penalties before doing this with a real loan.

This calculator supports monthly, bi-weekly, and weekly payment frequencies. Here, bi-weekly (26 per year) and weekly (52 per year) options split the loan into equal payments over the same term, so total interest is nearly the same as monthly. A lender's accelerated bi-weekly plan pays half the monthly payment 26 times a year (13 monthly payments), which does shorten the loan; add the difference as an extra payment per period to model it. The calculator models a fixed interest rate only, not variable-rate loans.