Amortization Calculator

An amortization schedule is a complete table showing every payment over a loan's life. Each row shows the payment number, date, amount applied to principal, amount applied to interest, and remaining balance. Early payments are mostly interest; later payments are mostly principal. The schedule makes this shift visible.

Interest is calculated on the outstanding balance. At the start, the balance is highest so interest charges are largest. As you make payments and the balance decreases, less goes to interest and more to principal. On a 30-year $300,000 mortgage at 6%, the first payment is $500 principal and $1,500 interest; the last payment is nearly all principal.

Extra payments go directly toward principal, reducing the balance faster. This reduces future interest charges and shortens the loan term. Even $100 extra per month on a 30-year mortgage can cut 5-7 years off the loan and save tens of thousands in interest. The calculator shows the impact on every future payment.

Yes — the calculator shows total interest with and without extra payments, the difference in total cost, and how many payments are eliminated. You can model one-time extra payments, recurring monthly extras, or annual lump-sum contributions to find the strategy that works for your budget.

Yes — copy the complete amortization table or download it for import into Excel or Google Sheets. The export includes payment number, date, total payment, principal portion, interest portion, extra payment, and remaining balance for every payment period.