Amortization schedule
Every payment, broken down. See how each dollar splits between principal and interest, when the loan will be paid off, and how extras shrink the schedule.
No loan configured yet
Enter a loan amount, rate, term, and first payment date on the calculator. Your full amortization schedule and chart will appear here.
Configure your loanAdvertisement
How amortization works
Every month you make the same total payment, but it splits two ways — part covers the interest your lender charges, and the rest chips away at the balance you borrowed. Because interest is charged on the balance you still owe, that split shifts a little every single month.
At the start, your balance is at its highest, so most of the payment goes to interest and only a sliver touches the principal. As the balance falls, the interest portion shrinks and more of each payment attacks the principal — which is why the early years feel slow and the final years move fast.
Monthly payment = P · r · (1 + r)ⁿ ÷ [ (1 + r)ⁿ − 1 ]
Here P is the amount borrowed, r is your monthly rate (the annual rate divided by 12), and n is the total number of payments. Each month the interest due is simply your current balance × r; whatever is left of the payment reduces the principal.
A worked example
Take a $300,000 loan at a 6.5% fixed rate over 30 years. The monthly principal-and-interest payment comes to about $1,896 — and the schedule above shows exactly where each dollar goes.
- Your very first payment is $1,625 interest and just $271 principal.
- Principal does not overtake interest until payment #233 — nearly 20 years in.
- Across the full term you pay roughly $382,633 in interest — more than the original loan itself.
None of that is a penalty or a hidden fee; it is simply how interest on a large balance adds up over decades. Seeing it broken out month by month is the whole point of an amortization schedule — and the reason it is worth studying before you sign.
How extra and biweekly payments change the math
Because interest is charged on the balance that remains, anything that lowers the balance sooner saves you interest on every payment that follows. The savings compound in your favor.
- Extra principal: adding just $100 a month to the example above pays the loan off about four years early — roughly 26 years instead of 30 — and saves tens of thousands in interest.
- Biweekly payments: paying half your payment every two weeks adds up to 26 half-payments a year, the equivalent of 13 monthly payments — one extra payment annually, with the same accelerating effect.
Switch on the extra-payment and biweekly options in the calculator above to see how they reshape your own payoff date and total interest.
Frequently asked questions
Why is almost all of my early payment interest?
Because interest is charged on the balance you still owe, and at the start of the loan that balance is at its highest. The interest portion is largest in month one and shrinks every month after as you pay the principal down.
Does the schedule change if my interest rate is fixed?
With a fixed rate your total monthly payment never changes, but the split between principal and interest shifts a little every month. The entire schedule is predictable from day one. Adjustable-rate loans re-amortize whenever the rate resets.
How much can extra payments actually save?
Often more than people expect, because the savings compound. On a $300,000 loan at 6.5%, an extra $100 a month trims about four years off the term and saves tens of thousands in interest. Use the extra-payment field above to see your exact numbers.
What is the difference between the loan term and the amortization period?
For most fixed-rate mortgages they are the same — a 30-year loan amortizes over 30 years. They differ only in products like balloon loans, where payments are amortized over a longer period than the term, leaving a lump sum due at the end.
Can the schedule show my exact payoff date?
Yes. The calculator projects the precise month your balance reaches zero, and it updates that date instantly when you add extra or biweekly payments.