See your monthly payment and a full amortization schedule with total interest.
Calculated instantly in your browser — your figures never leave your device.
How is loan amortization calculated?
Payment = P × r × (1 + r)^n ÷ ((1 + r)^n − 1), where P is the principal, r is the monthly rate (annual ÷ 12 ÷ 100) and n is the number of months. Each month, interest = balance × r and the rest reduces the balance. Early payments are mostly interest. A 250,000 loan at 6.5% over 30 years is about 1,580 per month and roughly 318,900 total interest.
Understanding your result
Early payments are mostly interest; over time more goes to principal. Extra payments reduce the balance faster, saving interest and shortening the loan.
Formula and method
Payment = P × r × (1 + r)^n ÷ ((1 + r)^n − 1), where P is the principal, r is the monthly rate (annual ÷ 12 ÷ 100) and n is the number of months. Each month, interest = balance × r and the rest of the payment reduces the balance.
Assumptions and limitations
The schedule assumes a fixed rate and equal payments. It excludes taxes, insurance, fees and any rate changes, so treat it as a close estimate.
Worked example
A 250,000 loan at 6.5% over 30 years has a payment of about 1,580 per month and roughly 318,900 in total interest.
How to use this tool
- Enter the loan amount, rate and term.
- Optionally add an extra monthly payment.
- Press Calculate to see the payment, totals and schedule.
Common mistakes to avoid
- Entering the monthly rate instead of the annual rate.
- Forgetting that taxes and insurance are not included.
About the Amortization Calculator
See exactly how a loan is paid off over time. The amortization calculator shows your monthly payment, the split between principal and interest, total interest and a full schedule you can export.
Who should use this tool
Anyone with a mortgage, car loan or personal loan who wants to understand the real cost and see how extra payments shorten the term.
Benefits
- Know your monthly payment before you commit.
- See how much of each payment is interest versus principal.
- Test how extra payments cut the term and interest.
- Download the full schedule as CSV.
Practical use cases
- Comparing loan offers by seeing the total interest each option costs over its full term
- Estimating how much a regular extra payment could shorten the loan and reduce interest
- Checking how much of an early payment goes to interest versus reducing the principal
- Exporting a month-by-month schedule to plan repayments or share with a co-borrower
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Frequently asked questions
How do extra payments help?
Every extra amount goes straight to the principal, so you owe less interest next month and pay the loan off sooner.
Can I download the schedule?
Yes. Use the download button to export the full month-by-month schedule as a CSV file.
Is my financial data stored?
No. All calculations run locally in your browser and nothing is sent to a server.