How to use the Amortization Calculator
Enter the loan amount, annual interest rate, loan term and extra payment per month and the result appears straight away. Everything runs in your browser, so nothing you type is uploaded.
The formula
Interest each month = balance × monthly rate; principal = payment − interest.
Examples
- $200,000 at 6% for 30 years
Monthly payment: $1,199.10 Payoff: 360 months (30.0 years) Total interest: $231,676.38
- Same loan with an extra $200 each month
Monthly payment: $1,199.10 (+ $200.00 extra) Payoff: 252 months (21.0 years) Total interest: $151,875.87 Interest saved with extra payments: $79,800.51; 108 months sooner.
- $200,000 at 6% for 15 years
Monthly payment: $1,687.71 Payoff: 180 months (15.0 years) Total interest: $103,788.46
Limitations and assumptions
Fixed-rate, fully amortizing loan with monthly payments. Lender fees, insurance and taxes are not included unless stated. Your lender's official disclosure takes precedence.
Frequently asked questions
What does amortization mean?
It is paying off a loan in equal instalments where early payments are mostly interest and later payments are mostly principal.
Why is so much of my early payment interest?
Interest is charged on the remaining balance, which is highest at the start, so the same payment covers less principal early on.
How do extra payments help?
Extra money goes straight to principal, which lowers the balance that future interest is charged on and shortens the loan.
Does this include taxes and insurance?
No. For a full home payment including taxes, insurance and HOA, use the mortgage calculator.