An amortization calculator shows how a fixed-payment loan is paid off over time. For a typical U.S. fixed-rate mortgage, auto loan, or personal loan, each monthly payment is split between interest and principal. Early in the loan, a larger share of the payment usually goes to interest. As the balance gets smaller, more of each payment goes toward principal.

Loan amortization calculator calculates the monthly principal and interest payment, total interest, payoff month, yearly amortization schedule, and how much interest can be saved by making extra principal payments.

The calculator uses the standard fixed-payment amortization formula:

In this formula, M is the monthly principal and interest payment, P is the loan amount, r is the monthly interest rate, and n is the total number of monthly payments. For example, a 30-year mortgage has 360 monthly payments, while a 15-year mortgage has 180 monthly payments.

In the United States, a borrower’s actual monthly housing payment is often larger than the principal and interest payment. Many mortgage payments also include property taxes, homeowners insurance, private mortgage insurance (PMI), and sometimes HOA dues. For that reason, this calculator separates monthly P&I from the estimated monthly total.

This distinction is useful because principal and interest determine the amortization schedule, while taxes and insurance affect affordability and monthly cash flow. If you are comparing loan offers, focus on the principal and interest payment, APR, fees, and total interest. If you are budgeting for homeownership, also include taxes, insurance, PMI, HOA, utilities, maintenance, and emergency reserves.

A key difference in this calculator is the extra payment impact section. Extra payments are applied directly to principal, so they reduce the balance faster. A lower balance means future interest is calculated on a smaller amount. This can shorten the payoff period and reduce total interest paid.

You can test three extra payment strategies:

Although many people search for an amortization calculator for mortgages, the same amortization logic can be used for many fixed-rate installment loans. For a mortgage, you may want to include tax, insurance, PMI, and HOA estimates. For an auto loan or personal loan, you can usually leave those optional housing-cost fields at zero and focus on principal, interest rate, loan term, and extra payments.

The yearly amortization schedule summarizes how much principal and interest you pay each year. The first 12 payments preview shows the month-by-month breakdown at the beginning of the loan. If the first payment has a high interest share, that is normal for a long-term loan because the outstanding balance is still near the original loan amount.

This calculator provides an estimate based on your inputs. Your actual mortgage payment and total loan cost may differ depending on your lender, location, credit score, loan type, down payment, taxes, insurance, PMI, HOA dues, closing costs, and discount points. It also does not account for APR calculations, adjustable-rate mortgage changes, escrow adjustments, late fees, refinance costs, prepayment penalties, or tax deductions.