How to Use the Loan Calculator
Enter the total amount you want to borrow in the Loan Amount field.
Enter the annual interest rate as a percentage (e.g. 5 for 5%).
Enter the loan term as the total number of monthly payments (e.g. 60 for 5 years).
Click Calculate to see your monthly payment, total paid, and full amortization schedule.
Use Export PDF to save a copy of the results.
How the Amortization Formula Works
Each monthly payment M is calculated from M = P x [r(1+r)^n] / [(1+r)^n - 1], where P is the loan principal, r is the monthly interest rate (annual rate divided by 12, then by 100), and n is the total number of payments. Every payment first covers that month's interest (the remaining balance multiplied by r), and the rest reduces the principal. Because interest is charged on the outstanding balance, early payments are weighted heavily toward interest. As the balance falls over time, more of each payment goes toward principal until the loan is fully repaid.
Worked Example
- Enter a loan amount of 10,000.
- Enter an annual interest rate of 5 (for 5% per year).
- Enter a term of 60 months (5 years).
- Click Calculate. The monthly payment will be approximately 188.71.
- Total paid over 60 months is approximately 11,322.74, of which 1,322.74 is interest.
- In month 1, roughly 41.67 goes to interest and 147.04 to principal. By month 60, nearly the full payment is principal.
- Scroll down to the amortization table to see the exact split for every month.
When to Use This Calculator
- Before applying for a personal loan, auto loan, or home improvement loan
- Comparing two loan offers with different interest rates or repayment terms
- Deciding how many months to spread payments over to keep them affordable
- Estimating total interest paid over the life of a loan
- Understanding how a larger down payment reduces total interest charged
- Verifying a lender's quoted monthly payment before signing
Important Note
Results are estimates based on a fixed interest rate and equal monthly payments. They do not include origination fees, insurance, taxes, prepayment penalties, or any costs beyond the stated interest rate. For variable rate loans, actual payments will change as the rate moves. Always confirm figures with your lender before making financial decisions.
Fixed Rate vs. Variable Rate Loans
Key Features
Full Amortization Schedule
See exactly how each monthly payment splits between principal and interest, from month one through the final payment.
Any Fixed Rate Loan
Personal loans, auto loans, home improvement loans, and mortgages all follow the same amortization formula this calculator uses.
PDF Export
Download a formatted PDF with key figures and the full amortization table, ready to share or file.
100% Private
All calculations happen locally in your browser. No data is sent to any server.
Privacy and Security
This calculator runs entirely in your browser using JavaScript. No loan amounts, rates, or results are transmitted to any server, stored, or logged. It is safe to use with real financial figures.
Frequently Asked Questions
What formula does this calculator use?
The standard amortization formula: M = P x [r(1+r)^n] / [(1+r)^n - 1], where P is the principal, r is the monthly interest rate (annual rate divided by 12 and then by 100), and n is the total number of monthly payments.
Why do early payments have more interest?
Interest each month is a percentage of the remaining balance. Early on the balance is highest, so interest takes up most of the payment. As the principal decreases, each payment covers more principal and less interest.
Can I use this for a mortgage?
Yes. A standard fixed rate mortgage uses the same formula. Enter the loan amount, annual rate, and term in months (e.g. 360 for 30 years). The result does not include property taxes, insurance, or PMI.
What if the interest rate is 0%?
Zero percent rates are supported. The monthly payment is the principal divided by the number of months, and total interest is zero.
Does this support extra payments or lump sum payoffs?
This calculator assumes equal monthly payments with no extra contributions. For scenarios with variable payments, a dedicated amortization tool with extra payment support would give more accurate results.