PayoffTable

Mortgage Amortization Calculator

Start from the loan amount itself — the number on your Loan Estimate or closing disclosure — and see the complete monthly breakdown of principal, interest, and remaining balance.

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

Your numbers

Amount you borrow
Your note rate
In years

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Most mortgage calculators want to start from a home price. That is the wrong starting point when you already have a loan in hand: you have a Loan Estimate, a closing disclosure, or twelve months of statements, and the number that matters is the amount actually borrowed.

This calculator takes the loan amount directly. Enter it with your note rate and remaining term, and you get the full monthly schedule — the same shape of table your servicer produces, but one you can interrogate, print, or export. It is also the fastest way to sanity-check a refinance quote: run the new loan's numbers here and compare the total interest against your current payoff projection.

The math is exact: monthly interest equals balance × (APR ÷ 12), and each payment is applied interest-first. No estimates, no rounding until the final payment, which is adjusted to the cent.

How mortgage amortization works

A fixed-rate mortgage amortizes on a simple monthly schedule. The payment is fixed at the start; the split between principal and interest is recalculated every month against the current balance. The formula for the fixed payment is:

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

Then, for each month: interest = balance × r; principal = payment − interest; new balance = balance − principal. Repeat until the balance reaches zero. Our schedule shows each of those steps explicitly, which is why it reconciles to the penny with servicer statements.

Worked example. Loan $250,000 at 6.5% for 30 years: monthly payment $1,580.17. Month 1: $1,354.17 interest, $226.00 principal. Month 120: $1,150.34 interest, $429.83 principal. Total interest: $318,861.22. The same loan at 5.5% would cost $261,010.10 — a $57,851.12 reason to care about the rate.

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

Where do I find my loan amount, rate, and remaining term?
The original principal and rate are on your closing disclosure. The current balance is on any monthly statement or your servicer's portal. Remaining term = original term minus payments you have already made (roughly — extra payments shorten it).
Why doesn't my servicer's balance match this schedule exactly?
Small differences come from daily-interest accrual at closing, payment posting dates, and rounding conventions. Over a full month the differences are cents; if you see a larger gap, check whether your servicer applies payments on a different date than your assumed first payment month.
Is the interest calculated monthly or daily?
This calculator uses the standard monthly convention (APR ÷ 12), which matches the amortization schedule in your loan documents. Servicers accrue interest daily between payments, but scheduled monthly charges reconcile to the same numbers.
How do extra payments change the amortization schedule?
Every extra dollar goes straight to principal, permanently reducing every future interest charge. Use the mortgage payoff calculator to see the rescheduled timeline with extras included.

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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