PayoffTable

Amortization Calculator

Enter a home price and down payment to see your full amortization schedule — every monthly payment split into principal and interest, your payoff date, and total interest.

Reviewed by the PayoffTable editorial team · Updated 2026-10-24

Your numbers

Total purchase price
Cash you pay at closing
Annual rate on the loan
15, 20, or 30 years are most common

Runs entirely in your browser. Nothing is uploaded.

An amortization schedule is the honest picture of a mortgage. The lender's number — your monthly payment — never changes, but what happens inside it changes constantly. In month one of a $340,000 loan at 6.5%, $1,841.67 of your $2,149.03 payment is interest and only $307.36 pays down the balance. The principal share does not overtake the interest share until month 233.

This calculator shows that flip happening, month by month. It starts from the purchase side (home price and down payment) because that is how most people actually frame the question — and it matters, because the down payment shrinks the loan before a single interest charge is calculated.

Everything runs in your browser. Nothing you type is sent anywhere, and you can print the schedule or download it as a CSV to keep next to your loan documents.

How the amortization calculation works

Your monthly principal-and-interest payment is calculated once, at closing, and never changes. It is the fixed payment that exactly pays off the loan over the term at your note rate:

M = P · r(1+r)ⁿ / ((1+r)ⁿ − 1) r = APR ÷ 12, n = months

Each month, the interest charge is simply the current balance multiplied by the monthly rate. Whatever is left of your payment after that interest charge goes to principal. Because the balance is highest at the start, early payments are mostly interest; each payment shrinks the balance slightly, so the next payment contains slightly more principal. That is the whole mechanism — no compounding tricks, no hidden fees in the schedule itself.

Worked example. Home price $425,000, down payment $85,000 → loan $340,000 at 6.5% for 30 years. Monthly payment = $2,149.03. First payment: $1,841.67 interest + $307.36 principal. Payment 233 (the crossover): $1,076.33 principal vs $1,072.70 interest. Total interest over the full term: $433,651.26. Payoff: month 360 (Oct 2056).

Terms & definitions

Amortization
The process of paying off a loan with scheduled payments that cover both interest and principal. Early payments are mostly interest; later payments are mostly principal.
Principal
The amount you borrowed and still owe. Extra payments reduce principal directly, which shrinks every future interest charge.
APR
Annual Percentage Rate — the yearly cost of the loan including fees. Your monthly interest charge uses the note rate, which is usually a touch lower.
Term
The number of years the loan is scheduled to last. A 30-year term has lower payments but roughly double the total interest of a 15-year term at the same rate.

Frequently asked questions

Why is so much of my early payment interest?
Interest is charged on the outstanding balance, which is at its highest at the start of the loan. On a $340,000 loan at 6.5%, the first month's interest alone is $1,841.67. As the balance falls, the interest share of each payment falls with it — this is the amortization curve, not a penalty.
Does this include property taxes and insurance?
No — the schedule covers principal and interest only, which is what the amortization schedule on your loan documents shows. If you escrow taxes and insurance, your total monthly check to the servicer is higher; those items are not part of the loan's amortization.
What is the difference between a 15-year and 30-year amortization?
At the same rate, a 15-year term roughly doubles the monthly payment but cuts total interest by about 55%. On $340,000 at 6.5%, the 30-year schedule costs $433,651 in interest; the 15-year costs $193,118 — a $240,534 difference.
Can I get an amortization schedule for an existing loan?
Yes — use our mortgage payoff calculator with your current balance and remaining years. It produces the forward-looking schedule from where you are now, including the effect of extra payments.

References

  1. Consumer Financial Protection Bureau — Loan Estimate explainer (how principal, interest, and amortization appear on your closing documents)
  2. CFPB — What is an amortization schedule?
  3. Federal Reserve — Mortgage origination resources (APR vs note rate)
Educational content only — not financial, tax, or legal advice. Your loan terms govern; confirm details with your servicer.

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