Amortization Schedule Calculator
Calculate your monthly payment and view a full amortization schedule with extra payment options, interest savings, and yearly/monthly toggle.
Monthly Payment
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Total Interest
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Total Cost
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Interest Saved
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Time Saved
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Monthly schedule
| Month | Payment | Principal | Interest | Balance |
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What is Amortization Schedule Calculator?
An amortization schedule shows exactly how each loan payment is split between principal and interest over the life of the loan. Early payments are mostly interest; later payments are mostly principal. This calculator lets you add extra monthly payments and a one-time lump sum payment to see exactly how much interest you save and how many years you cut off the loan. Toggle between monthly and yearly summary views.
How to use
- 1 Enter the loan amount, annual interest rate, and loan term in years.
- 2 Optionally add an extra monthly payment to see interest savings.
- 3 Optionally add a one-time extra payment and the month it will be made.
- 4 Toggle between Monthly and Yearly views for the amortization table.
- 5 Review total interest savings and time saved shown above the table.
Formula
Example calculation
A $200,000 loan at 7% for 30 years: base payment ≈ $1,331/mo, total interest ≈ $279,000. Adding $200/mo extra saves about $72,000 in interest and pays off 8 years early. A $10,000 one-time payment in month 12 saves an additional $18,000.
Frequently asked questions
Why do early payments go mostly to interest?
Because interest is calculated on the outstanding balance, which is highest at the start. As you pay down principal, less interest accrues each month — this is called amortization.
How much does an extra $100/month save?
On a $200,000 mortgage at 7% for 30 years, an extra $100/month saves roughly $30,000 in interest and cuts about 4 years off the loan. Larger extra payments have a proportionally larger effect.
What is a lump sum payment?
A one-time extra payment applied to principal in a specific month. Large lump sums (like a bonus or tax refund) applied early in the loan can save a disproportionate amount of interest because they reduce the balance during the highest-interest period.
What is negative amortization?
Negative amortization occurs when payments are too small to cover interest, causing the balance to grow. This calculator assumes fully amortizing payments that eliminate the balance by the end of the term.
Should I make extra payments or invest the money?
Compare your mortgage rate to your expected investment return after tax. If your mortgage rate is 7% and your expected after-tax investment return is 6%, paying down the mortgage is the better guaranteed return. If the investment return is higher, investing may be preferable.