Loans · amortization schedule

Amortization calculator

Enter a loan amount, rate and term to see the monthly payment — then read the full year-by-year schedule of how each payment splits between principal and interest while the balance falls to zero.

Monthly payment —

Total interest: —
Total paid: —

Where the payment goes — first year vs. last

Interest is front-loaded: early on, most of each payment is interest, so the balance barely moves. By the final year almost every dollar goes to principal.

Amortization schedule

Year by year — principal paid, interest paid & remaining balance

Year	Principal paid	Interest paid	Remaining balance

What amortization actually means

When you borrow money on a fixed-rate loan, you don’t pay the interest and the balance off separately — you make one level payment, month after month, and the lender splits it for you behind the scenes. That splitting is amortization. The word simply describes spreading a debt across equal payments so that, by the end of the term, the balance lands exactly on zero. A mortgage, a car loan, a student loan and a personal loan all amortize the same way; only the amount, rate and term change.

The calculator above takes those three inputs — loan amount, annual interest rate, and term in years — and returns the fixed monthly payment, the total interest you’ll pay over the life of the loan, and the total of all payments. But the real deliverable is the table beneath it: the full amortization schedule, year by year.

How each payment splits between principal and interest

Here’s the part that surprises most borrowers. Your monthly payment never changes, but what it’s made of changes every single month. Interest is charged on the remaining balance, and at the start of the loan that balance is at its peak — so the interest slice of your first payment is as large as it will ever be. Whatever is left after covering that interest goes to principal, the part that actually reduces what you owe.

Because the balance starts high, that leftover principal is tiny at first. As the months pass and the balance falls, the interest charge falls with it, so a bigger share of the same payment goes to principal. The effect snowballs: principal rises, interest shrinks, and the balance drops faster and faster toward the end. This is why people say interest is front-loaded — on a 30-year mortgage, you can be several years in before principal even matches interest in a given payment. The “first year vs. last year” bar in the tool makes the flip visible at a glance: early bars are mostly the deep interest color, the final year is almost entirely principal.

How to read the schedule

The schedule table aggregates the monthly math into one row per year, which is the cleanest way to see the trend without scrolling through hundreds of payments. Each row has four columns:

Year — the year of the loan, counting from your first payment.
Principal paid — how much of that year’s payments went toward reducing the balance. This number grows every year.
Interest paid — how much went to the lender as interest. This number shrinks every year.
Remaining balance — what you still owe at the end of that year. It falls slowly at first, then accelerates, reaching essentially zero in the final year.

Read it top to bottom and you’ll watch the principal and interest columns trade places. Add the interest column down the whole table and you get the total interest figure shown up top — often a sobering share of the amount you originally borrowed.

Why extra principal payments save so much

Once you understand the front-loading, the most powerful move becomes obvious. Any extra principal payment permanently removes that money from the balance, which means you never pay interest on it again for the entire remaining life of the loan. Pay an extra amount in year two of a thirty-year mortgage and you’re wiping out interest that would otherwise have accrued on that sum for twenty-eight more years.

That’s why even modest extra payments, made early, can knock years off the term and save tens of thousands in interest. The savings come not from the size of the extra payment but from how long it would otherwise have sat there racking up interest. Later in the loan, when the balance is already small and mostly principal anyway, extra payments help much less — another reason to act early. To model the exact savings, run the early payoff calculator.

Works for any fixed loan

Don’t let the mortgage examples fool you — this is universal. A $30,000 auto loan at 7% over 5 years amortizes on the same curve as a $400,000 mortgage at 6.5% over 30 years. The shorter the term and the lower the rate, the less front-loaded the interest and the less you pay overall; the longer the term, the more dramatic the front-loading. Drop your own numbers in and the schedule rebuilds instantly, so you can compare a 15-year against a 30-year, or see what a point of rate really costs you over the full term.

Related tools & guides

Mortgage calculator — the full PITI payment including taxes, insurance and PMI, not just principal and interest.
Early payoff calculator — see exactly what extra payments save in interest and years off the term.
All calculators — browse the rest of our free money tools.

These figures are for planning and education, not financial advice. Your lender’s official disclosure is the authoritative one — confirm the exact numbers with them before you sign.

Amortization calculator FAQ

What is amortization?

Amortization is the process of paying off a loan in equal, scheduled payments over a fixed term. Each payment is the same size, but the share that goes to interest versus principal changes every month. The amortization schedule is the table that lays this out — payment by payment, or year by year — showing how much of each payment reduces your balance and how much is the lender’s interest charge, until the balance reaches zero at the end of the term.

Why is so much of my early payment interest?

Interest is charged on the remaining balance, and at the start of the loan that balance is at its largest, so the interest portion is biggest. With a level monthly payment, whatever is left after interest goes to principal — which early on is only a small sliver. As the balance shrinks, the interest charge shrinks too, so more of each identical payment attacks the principal. That’s why the split flips over time and why interest is described as front-loaded.

Does this work for auto and personal loans, not just mortgages?

Yes. Any fixed-rate, fixed-term loan amortizes the same way — a mortgage, a car loan, a student loan, or a personal loan. The only inputs that matter are the amount borrowed, the annual interest rate, and the term in years. A 5-year auto loan and a 30-year mortgage use the identical math; only the numbers differ, so this schedule is accurate for all of them.

How do extra principal payments save money?

Every extra dollar you put toward principal permanently removes that dollar from the balance, so you never pay interest on it again for the rest of the loan. Because interest compounds on the remaining balance, paying extra early has an outsized effect — it shaves interest off every future month and pulls your payoff date forward. On a long mortgage, modest extra payments can cut years off the term and save tens of thousands in interest.

Is the monthly payment fixed for the whole loan?

For a standard fixed-rate loan, yes — the payment stays the same from the first month to the last. What changes is the internal split: interest falls and principal rises each month. (On a mortgage, your total bill can still move if taxes or insurance held in escrow change, but the principal-and-interest portion this calculator shows is constant.)

Is this calculator accurate?

It uses the standard amortization formula that lenders use, so the monthly payment, total interest and year-by-year schedule are accurate for a fixed-rate loan. Real loan statements can differ by a few cents from rounding, and they may add fees, PMI or escrow that aren’t part of pure principal-and-interest amortization. Treat it as an accurate planning tool for the loan itself rather than a substitute for your lender’s official disclosure.