Loan Amortization Calculator
Understand how your loan gets paid off over time. See your monthly payment, total interest, and how extra payments can save you thousands.
How Loan Amortization Breaks Down
Amortization schedules show exactly where every dollar of your payment goes. Early payments are mostly interest because the loan balance is largest. Over time, the interest portion shrinks and the principal portion grows.
On a $25,000 loan at 6% over 10 years, your monthly payment is $277.54. Your first payment includes $125 in interest and $152.54 toward principal. By the final payment, only about $1.38 goes to interest and the rest pays off the remaining principal.
This front-loaded interest structure means extra payments early in the loan have the biggest impact. Paying an extra $100 in month one saves far more total interest than paying an extra $100 in month 100.
The Power of Extra Payments
Extra payments directly reduce your principal, which lowers the interest charged on future payments. Even small amounts compound into huge savings over time.
Adding just $50 per month to a $25,000 loan at 6% cuts the payoff time from 120 months to about 100 months—nearly two years sooner. You'll save around $950 in total interest. Bump that to $100 extra monthly and you save $1,900 while paying off the loan in 86 months.
The key is consistency. One-time lump sum payments help, but regular extra payments month after month create exponential savings because each payment reduces the base on which future interest is calculated.
When Not to Make Extra Payments
If your loan has a very low interest rate—say 2-3%—you might earn more by investing extra cash instead of paying down the loan. Historical stock market returns average 8-10%, so investing could net you 5-7% more than saving the 2-3% loan interest.
Also prioritize high-interest debt first. If you have credit card balances at 18% APR, pay those off before making extra payments on a 6% loan. Attack the highest-rate debt first to maximize your financial benefit.
Finally, maintain an emergency fund. Don't pour every spare dollar into loan payoff if you don't have 3-6 months of living expenses saved. Once tied up in your loan payoff, that money isn't accessible if you face a job loss or unexpected expense.
Frequently Asked Questions
What is loan amortization?
Amortization is the process of paying off a loan through regular, equal payments over time. Each payment includes both principal and interest, calculated so the loan is fully paid by the end of the term.
Why is most of my early payment interest?
Interest is calculated on your remaining balance. Early on, your balance is highest, so more of each payment goes to interest. As you pay down principal, interest shrinks and more goes toward the principal.
How much do extra payments really help?
Dramatically. An extra $100 per month on a $25,000 loan at 6% over 10 years saves about $1,900 in interest and pays off the loan 25 months early.
Should I make extra payments or invest the money?
It depends on your loan rate and investment returns. If your loan charges 8% and you can earn 10% investing, investing makes more sense. If your loan is 8% and investments return 5%, pay down the loan.
Do all extra payments go toward principal?
Usually, but not always. Some lenders apply extra payments to future interest unless you specify otherwise. Always designate extra payments as principal-only to maximize savings.