Loan Amortization Calculator
Generate a complete month-by-month amortization schedule for any loan. See how extra payments reduce interest and shorten your loan term.
Generate a complete month-by-month amortization schedule for any loan. See how extra payments reduce interest and shorten your loan term.
A full payment-by-payment schedule shows exactly how much of each payment is interest versus principal.
Model extra monthly payments and watch years — and thousands in interest — disappear.
Find when you'll truly own the house, and how to align it with retirement.
See the interest paid per year — the number some tax deductions are based on.
Build the schedule yourself and compare it against your statements. Misapplied payments, added fees and rate changes show up as a divergence you can point to in writing.
Early payments are mostly interest. The schedule shows exactly when principal overtakes it — on a long mortgage that can be more than a decade in, which surprises most borrowers.
An amortization schedule is a complete table showing every loan payment broken down into its interest and principal components, month by month. Early payments are mostly interest (e.g., Month 1 of a 30-year mortgage might be 80% interest, 20% principal). By the final payment, it flips to nearly all principal. The table also shows the remaining balance after each payment.
Adding $200/month extra to a $300,000 30-year mortgage at 7% saves approximately $90,000 in total interest and cuts the loan term by about 7 years. Even $100/month extra saves ~$50,000 and shortens by 4 years. Make sure to specify "apply to principal" when sending extra payments.
Monthly interest is calculated on the outstanding balance: Interest = Balance × (Annual Rate ÷ 12). In Month 1 of a $300,000 loan at 7%, interest = $300,000 × 0.5833% = $1,750. If the payment is $1,996, only $246 reduces principal. As balance falls over time, less interest accrues and more of each payment goes to principal.
Negative amortization occurs when monthly payments are too small to cover the interest charge — the unpaid interest is added to the loan balance, which grows over time. Some adjustable-rate mortgages (ARMs) and income-driven student loan repayment plans allow this. It is financially dangerous and should be avoided if possible.
Find your current loan's amortization schedule and note the remaining principal balance. Then calculate the new loan's total interest. Refinancing makes sense if (new total interest + closing costs) < remaining interest on current loan. The break-even point is typically 2–4 years — only refinance if you plan to stay that long.