What Is an Amortization Schedule?
An amortization schedule is the full breakdown of every payment over the life of a loan — showing exactly how much of each payment goes toward interest versus principal, and what your remaining balance is after each payment. It applies to any loan with a fixed rate and fixed term: mortgages, auto loans, personal loans, student loans, and most business loans all amortize the same way. This calculator builds that full schedule for you, with a view-toggle so you can see either a compact year-by-year summary or the complete month-by-month breakdown.
How Your Monthly Payment Is Calculated
Your fixed monthly payment is calculated from three inputs — the loan amount, the annual interest rate, and the number of months in the term — using the standard amortization formula. That same payment amount is used for every month of the loan. What changes month to month is how that payment is split: each month's interest charge is calculated on the current remaining balance, and whatever is left over after that interest goes toward reducing the principal.
Why Early Payments Are Mostly Interest
In the first years of a 30-year mortgage, for example, the majority of each payment goes to interest rather than principal — not because the lender is "front-loading" interest, but simply because the balance is at its highest point early on, and interest is always calculated on the current balance. As principal gets paid down, the interest portion of each payment shrinks and the principal portion grows, even though the total payment stays the same. This is why the equity you build accelerates dramatically in the later years of the loan.
Reading the Schedule
The annual view groups payments by calendar year, based on the first payment date you enter — useful for seeing how your balance declines over time at a glance, or for estimating mortgage interest for tax purposes. The monthly view shows every individual payment with its exact date, principal/interest split, and ending balance — useful for checking a specific month, verifying a lender's numbers, or seeing precisely when your balance crosses a threshold (for example, the 78% loan-to-value point relevant to PMI removal on a mortgage).