How to use this calculator
- Enter the loan amount, or a purchase price and down payment percentage to fill it in.
- Enter the interest rate, choose the term, and optionally set the month your payments start.
- Optionally add annual property tax, annual homeowners insurance, and monthly HOA dues for an all-in monthly estimate.
- Optionally add extra monthly principal or a one-time lump sum, then select Generate Schedule.
What the results show
- Monthly principal and interest, total interest, total principal and interest paid, and the payoff month.
- A yearly summary or a month-by-month table of principal, interest, and remaining balance.
- With extra payments: interest saved, months saved, and the new payoff month.
Frequently asked questions
What is a mortgage amortization schedule?
It is a table of every scheduled payment on a fixed-rate loan, showing how much of each payment goes to interest, how much goes to principal, and the balance left afterward. On a long-term loan, early payments are mostly interest and later payments are mostly principal.
Why does so little of my early payment go to principal?
Interest each month is charged on the remaining balance. The balance is largest at the start, so interest takes the biggest share of the payment. As the balance falls, the interest portion shrinks and more of the same payment reduces principal.
How do extra principal payments change the schedule?
Extra principal lowers the balance sooner, so later months accrue less interest and the loan can be paid off earlier. This calculator assumes every extra dollar is applied to principal in the month you choose. Ask your servicer how it applies extra payments and whether any prepayment terms apply to your loan.
Does the monthly payment include taxes and insurance?
The schedule itself covers principal and interest only. If you enter property tax, homeowners insurance, or HOA dues, the calculator adds a separate all-in monthly breakdown. It does not estimate mortgage insurance.
Does this work for adjustable-rate loans?
The schedule assumes the rate stays the same for the whole term, so it fits fixed-rate loans. For an adjustable-rate mortgage, use the ARM adjustment calculator to see how the payment could change when the rate resets.
Lighthouse provides educational information, not a personal loan quote, lending decision, or legal or financial advice. Results are estimates based only on the numbers you enter. Verify the figures against your documents and ask your lender, servicer, or a qualified professional about your circumstances.