What is a Mortgage Amortization Calculator?
A mortgage amortization calculator helps you predict exactly how your mortgage payments will pay down your home loan over time. "Amortization" refers to the process of spreading out a loan into a series of fixed payments over a set period. Although your monthly payment usually remains the same, the portion that goes towards the principal (the actual loan amount) and the portion that goes towards interest will change every month.
At the beginning of your loan term, the vast majority of your monthly payment goes toward paying off the interest. As time passes, the principal balance slowly decreases, meaning less interest accrues each month. Eventually, a larger portion of your payment begins covering the principal. This calculator provides a visual schedule so you can see exactly when you will break even and finally pay off your house.
How to Use This Calculator
This tool requires a few basic inputs to generate your amortization schedule. It also allows you to factor in advanced costs like property taxes and insurance to give you a highly accurate estimate of your true out-of-pocket monthly costs.
- Home Price: The total purchase price of the property you are buying.
- Down Payment: The amount of money you are paying upfront in cash. The standard benchmark is 20%, but many loans allow for 3%, 5%, or 10% down. (Subtracting your down payment from the home price equals your actual loan amount).
- Loan Term: The lifespan of the loan. In the US, 30-year fixed and 15-year fixed loans are the most common terms.
- Interest Rate: The annual percentage rate charged by your lender for borrowing the money.
- Advanced Options (Taxes & Fees): You can expand this section to input your estimated annual property taxes, annual homeowner's insurance, and any monthly HOA fees. This helps calculate your total "PITI" payment (Principal, Interest, Taxes, and Insurance).
- Extra Payment: Adding extra money to your monthly payment is one of the most effective ways to accelerate your payoff date and save thousands of dollars in interest. Entering a value here will recalculate the amortization table to show your savings.
The Mortgage Payment Formula (P&I)
The standard mathematical formula used by banks and lenders to calculate the monthly Principal and Interest (P&I) payment is:
M = Total monthly payment (P&I)
P = Principal loan amount (Home Price - Down Payment)
r = Monthly interest rate (Annual Rate / 12 months)
n = Number of payments (Years × 12)
Keep in mind that this formula only calculates the base mortgage loan. If your lender uses an escrow account for property taxes and insurance, those costs will be divided by 12 and added on top of your M value.
Frequently Asked Questions
PITI stands for Principal, Interest, Taxes, and Insurance. These are the four standard components of a typical monthly mortgage payment. Principal and interest go to the lender to repay your loan, while taxes and insurance go into an escrow account to pay your local government and insurance provider when those bills are due.
The easiest way to pay off your mortgage ahead of schedule is by adding an extra amount directly to the loan principal each month. Even an extra $50 or $100 per month can shave off several years and save you thousands of dollars in interest over the lifespan of a 30-year loan. You can use the "Extra Payment" field in the Advanced Options of this calculator to see exactly how much you could save.
Interest is calculated every month based on your current outstanding principal balance. In the first few years of a mortgage, your principal balance is at its absolute highest, which means the interest accrued for that month is also at its highest. As you slowly chip away at the principal over the years, the monthly interest charge decreases.
While 20% is considered the traditional "gold standard" to avoid paying Private Mortgage Insurance (PMI), many borrowers put down much less. FHA loans allow for down payments as low as 3.5%, and some conventional loans allow 3%. VA and USDA loans can even offer 0% down for eligible borrowers. However, a larger down payment means a smaller loan, which results in lower monthly payments and less total interest paid.
Yes. Regardless of whether you have a mortgage or own your home outright, property taxes and home insurance are ongoing costs of homeownership. If you have a mortgage, your lender will typically require you to pay these costs monthly through an escrow account to ensure the property (their collateral) is protected and tax liens are avoided.