What is an amortization schedule?

An amortization schedule is a complete table showing every loan payment from first to last, broken down into the principal portion (reduces your balance) and the interest portion (cost of borrowing). Early payments are heavily weighted toward interest; later payments shift toward principal. A 30-year mortgage might have 360 rows — one per monthly payment.

Why do early payments go mostly to interest?

Because interest is calculated on the remaining balance. At the start of a loan, your balance is highest — so the interest charge is highest. Your payment minus that large interest charge leaves only a small amount to reduce principal. As the balance slowly falls, the interest portion shrinks and the principal portion grows. This is why the payoff curve is not linear.

How much does one extra payment per year save?

On a typical 30-year mortgage, one extra full payment per year (applied to principal) reduces the loan term by about 4–5 years and saves tens of thousands in interest. The earlier in the loan term you start, the more dramatic the effect — because you're eliminating high-interest future payments.

What's the difference between a 15-year and 30-year mortgage?

A 15-year mortgage typically has a lower interest rate (often 0.5–0.75% less) and you pay interest for only half as long. On the same loan amount, a 15-year pays dramatically less total interest — but the monthly payment is higher, often 40–50% more than the 30-year payment. Use the rate comparison section to see both scenarios side by side.

Can I use this for any loan type?

Yes — the calculator works for any fixed-rate, fully-amortizing loan: mortgage, auto loan, personal loan, student loan, or business loan. All you need is loan amount, interest rate, and term. Variable-rate loans are more complex as the schedule changes when the rate adjusts.

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Amortization Calculator

How much are you really paying for that loan?

What This Does

An amortization schedule reveals the uncomfortable truth about loans: in the early years, almost every payment goes to interest, not principal. On a 30-year mortgage at 7%, your first payment is roughly 88% interest. After five years of payments, you've paid about $120,000 but reduced your balance by only $15,000. Understanding this front-loading effect changes how you think about loans and extra payments. An extra $100/month toward a 30-year mortgage in year one doesn't just eliminate one payment — it eliminates months from the back end of the schedule, where you'd otherwise be paying almost pure interest. This calculator generates the full amortization schedule for any loan: mortgage, auto, personal, or student. You can see exactly how much of each payment goes to interest vs. principal, your remaining balance at any point, and the precise impact of extra monthly payments on total interest paid and payoff date. Use it before taking out any loan to understand the true cost over time, not just the monthly payment. Use it on existing loans to model prepayment strategies — even small additional payments in the early years have disproportionate impact.

When Should You Use This?

→Before signing a mortgage — understand what 30 years of interest actually costs
→Comparing 15-year vs. 30-year loan terms on total interest paid
→Modeling extra monthly payment strategies to reduce total interest
→Verifying your lender's payment breakdown is accurate
→Understanding how much equity you'll have at any point in your loan
→Deciding whether to refinance by seeing remaining interest on your current loan

Example Scenario

Marcus takes out a $400,000 mortgage at 6.75% for 30 years. Monthly payment: $2,594. The amortization table shows his first payment splits as $2,250 interest / $344 principal — 87% interest. He models adding $400/month extra. The calculator shows he'd pay off 7 years early and save $187,000 in interest. He decides to split the difference: $200/month extra, saving $112,000 and cutting 4.5 years off the loan. That decision, made at signing, is worth more than any refinance he'll consider later.

📊Amortization Calculator

Loan Amortization Calculator

Enter loan amount, rate, and term to calculate monthly payment, total interest, balance curve, and extra payment impact. Results update live.

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Annual Interest Rate

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Extra Monthly Payment

Additional principal payment/month — see impact in Charts tab

Results are estimates only and do not constitute financial, tax, or legal advice. Always consult a qualified professional before making financial decisions.