Amortization Calculator

An amortization schedule is a complete table of loan payments broken down month by month. Each row shows the payment amount, how much goes toward principal, how much goes toward interest, and the remaining balance. Early in the loan, most of each payment covers interest. Over time, more goes toward principal. This calculator shows the full schedule grouped by year.

Extra payments go entirely toward reducing your principal balance. Because interest is calculated on the remaining balance, a lower principal means less interest accrues each month. This creates a compounding effect: each extra payment saves you not just the interest on that dollar, but on all future months too. Even $100–$200 extra per month can cut years off a 30-year mortgage and save tens of thousands in interest.

On a $250,000 loan at 6.5% over 30 years, an extra $200/month saves approximately $67,000 in interest and pays off the loan 7 years early. The savings are larger earlier in the loan term, because that is when your balance, and therefore your interest accrual, is highest.

A standard loan calculator tells you your monthly payment. This amortization calculator focuses on the full payment schedule and, most importantly, shows you the exact impact of making extra payments. You can see month by month how your balance declines, and compare scenarios with different extra payment amounts.

Yes. The extra payment you enter is applied as an additional principal payment every month for the life of the loan. Some people instead make one large extra payment per year (like a tax refund). To model that, divide your annual extra payment by 12 and enter that as your monthly extra.

Yes, completely. All calculations run in your browser. No loan amounts, rates, or payment data are ever sent to a server. Your inputs are saved locally in your browser for convenience.