Loan Tools
Amortization
Calculator
Enter any loan amount, term, and rate to get your monthly payment and a complete year-by-year repayment schedule. See exactly how extra payments cut your interest.
Configure
Loan parameters
Schedule
Yearly amortization breakdown
| Year | Interest | Principal | Toward principal | Ending balance |
|---|---|---|---|---|
| 1 | $11,769 | $8,483 | 42% | $191,517 |
| 2 | $11,246 | $9,007 | 44% | $182,510 |
| 3 | $10,690 | $9,562 | 47% | $172,948 |
| 4 | $10,101 | $10,152 | 50% | $162,796 |
| 5 | $9,475 | $10,778 | 53% | $152,018 |
Guide
How to Use the Amortization Calculator
01
Set Loan Parameters
Drag the sliders or type values for loan amount, term in years, and annual interest rate. Results update instantly as you adjust — no button press needed.
02
Add Extra Payment
Enter an optional extra monthly payment amount. The calculator immediately shows how much total interest you save and how many months sooner you pay off the loan.
03
Read the Schedule
Review the donut chart for principal/interest split, the summary stats, and the full year-by-year amortization table showing interest, principal, and balance for every year.
Explainer
How Loan Amortization Works
The Amortization Formula
For a fixed-rate loan the monthly payment is constant throughout the term. It's calculated as:
Where P = principal, r = monthly rate (annual ÷ 12 ÷ 100), n = total payments (years × 12). The result M stays fixed every month.
Why Early Payments Are Mostly Interest
Each month, interest is computed on the remaining balance. In month 1 on a $200,000 loan at 6%, interest = $200,000 × 0.005 = $1,000. If the monthly payment is $1,199, only $199 reduces the balance. As the balance falls, interest charges shrink and more of each payment goes to principal—this acceleration is what "amortization" refers to.
The Power of Extra Payments
Extra payments reduce the principal immediately, which lowers every future interest charge. A consistent extra $200/month on a $200,000, 30-year loan at 6% can eliminate ~5 years from the term and save $40,000+ in interest — because today's principal reduction compounds forward across all remaining months.
Amortization vs. Interest-Only
An amortizing loan fully retires the debt by the final payment — balance reaches exactly $0. Interest-only loans charge just the interest each period and leave the full principal outstanding at maturity. Most mortgages, auto loans, and personal loans are fully amortizing; some commercial real estate loans use interest-only periods followed by amortizing payments.
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FAQ
Amortization Calculator FAQ
What is an amortization schedule?
An amortization schedule is a table showing each payment period of a loan, broken down into how much goes toward interest and how much reduces the principal balance. Early payments are mostly interest; later payments are mostly principal. The NumeraFin Amortization Calculator shows this breakdown year by year.
How is the monthly payment calculated?
The standard amortization formula is: monthly payment = P × [r(1+r)^n] / [(1+r)^n - 1], where P is the loan principal, r is the monthly interest rate (annual rate ÷ 12 ÷ 100), and n is the total number of monthly payments (years × 12). For zero-interest loans, payment = P ÷ n.
How do extra monthly payments affect my loan?
Extra payments go entirely toward reducing the principal balance. Because interest is calculated as a percentage of the remaining balance, a lower balance means less interest accrues each month. This creates a compounding effect — each extra dollar paid today eliminates future interest charges on that principal for every remaining month of the loan.
What is the difference between total interest and total paid?
Total paid = loan principal + total interest. For example, a $200,000 loan at 6% for 30 years has a monthly payment of $1,199. Total paid over 30 years is ~$431,640, meaning total interest is ~$231,640 — more than the original loan amount.
Why does so much of my early payment go toward interest?
Because interest is calculated on the current outstanding balance. In the first month of a $200,000 loan at 6%, the interest charge is $200,000 × 0.5% = $1,000 — nearly the entire payment. As the balance decreases over time, the interest portion shrinks and the principal portion grows. This is the nature of amortizing loans.
Can I use this for a mortgage, auto loan, or student loan?
Yes. The amortization formula is the same for all fixed-rate installment loans — mortgage, auto, personal, or student loans. Enter the loan amount, rate, and term, and you get the correct monthly payment and schedule regardless of the loan type. Variable-rate loans will differ since the rate changes over time.
Disclaimer
This calculator is for informational and educational purposes only. Results are based on standard fixed-rate amortization math and do not account for variable rates, balloon payments, origination fees, mortgage insurance, property taxes, or other loan-specific terms. Always consult a qualified financial advisor or lender before making borrowing decisions. Actual loan terms may differ.