Amortization Schedule Calculator

Amortization is the schedule by which a fixed payment retires a loan. Every month the payment is the same, but what it buys changes: interest is charged on the balance you still owe, so early payments — when the balance is at its highest — are mostly interest, and the split shifts toward principal a little every month. The table makes this visible: watch the interest column fall and the principal column rise, row by row, until they cross.

Two things this schedule deliberately leaves out. It is principal and interest only — property tax, homeowner's insurance, and PMI ride on top of these figures in an escrow payment, and the mortgage calculator is the tool that adds them in. And it assumes a fixed rate: an adjustable loan re-derives its schedule at every reset, so this table describes an ARM only until its first adjustment.

The optional extra payment shows the schedule's other face. Extra money goes entirely to principal, so every later row accrues less interest and the table simply ends early — the rows that disappear are months you no longer owe. The extra payment calculator is the same idea framed as a comparison; this page shows it month by month.

The optional balloon date is the same arithmetic with a shorter fuse. A balloon loan sets its payment from a long amortization — often 30 years — but the loan itself ends early, and whatever balance remains on that date is due all at once. That lump is the balloon. Enter the due date above and the table stops there: on the $300,000 example with a balloon at year 7, seven years of $1,896.20 payments retire just $28,751.27 of principal, so the balloon is $271,248.73 — about 90% of what was borrowed, due in month 84. That one number is the whole shape of a balloon loan: the payment stays low precisely because most of the loan is never amortized, and the plan depends on refinancing, selling, or having the lump ready before it lands.

A worked example

Take the defaults: $300,000 at 6.5% for 30 years. The payment is about $1,896 a month. In month one, interest is $1,625 (that's $300,000 × 6.5% ÷ 12) and only $271 reaches the balance. The halfway point by time — year 15 — is nowhere near halfway by balance: you still owe about $218,000, nearly three-quarters of the original loan, because the early years bought so little principal. It's early in year 20 that a payment finally splits fifty-fifty. None of this is a trick or a penalty — it is just what charging interest on a declining balance looks like written out in full.

Common questions

Why is so much of my early payment interest? Interest is charged on what you still owe, and at the start you owe the most. As the balance falls, the interest share falls with it — the last years of the table look nothing like the first.

Does this include taxes, insurance, or escrow? No — an amortization schedule is the loan itself. Everything else in your monthly housing payment rides on top of these figures.

What happens if I pay extra? Extra payments go entirely to principal, so the schedule ends early. Enter an amount above and the table redraws shorter — and the receipt says what the missing months were worth.

What is a balloon payment? The balance still owed when a balloon loan comes due — deferred, not forgiven. The monthly payment is calculated as if the loan ran its full term, so it stays low; the trade is that the schedule stops early with most of the balance intact, and that remainder is due in one payment. Enter the balloon date above and the receipt prices it. Paying extra shrinks the balloon dollar for dollar, and the receipt shows that too.

This is an estimate assuming a fixed rate and on-time payments. Your servicer's schedule may differ by a few dollars from rounding, and by more if your rate adjusts or your payments vary.