Amortization Calculator
Build a month-by-month loan amortization schedule with extra payments.
5.0 (1 rating)Enter your values to see the result.
Results are estimates for planning only. Actual figures depend on your lender or bank, fees, rounding and the exact dates used, so confirm the numbers before you sign anything.
Processing and privacy
Processing varies by tool. Check the instructions for local processing, server requests, external services and any file or request limits before entering sensitive information.
Read the privacy policyHow this calculation works
Understand the method, inputs and limits behind your result.
- Formula
- Monthly payment = P × r / (1 − (1 + r)^−n). If r = 0, payment = P / n. Monthly interest = outstanding balance × r; principal repaid = payment − interest.
- Variables
- P = amount borrowed
- r = annual interest rate ÷ 100 ÷ 12
- n = number of monthly payments (years × 12)
- Units
- Principal and payments: selected currency
- Annual rate: percent
- Term: years or months
- Example
- Adding 200 a month to a 250,000 30-year loan at 6.5% saves over 90,000 in interest and pays it off years early.
- Assumptions
- Fixed rate and monthly payments. Principal and interest exclude taxes, insurance and fees; extra costs entered are added separately. Actual lender rounding and payment dates may differ.
- Source
- Last reviewed
- Implementation review; specialist review has not been recorded.
Methodology & References
The method depends on the selected model and input options. Review the assumptions and references above before interpreting the result.
- Enter the loan amount, rate and term.
- Add an optional extra monthly payment and the first payment date.
- Read the payment, payoff date and the full schedule.
Interpretation and limitations
- Why is most of the early payment interest? Interest is charged on the remaining balance, which is highest at the start.
- Do extra payments always go to principal? Usually, but confirm with your lender that extra payments reduce the principal.
References
Share this tool
Found it useful? Send it to a friend or teammate.
Rate this tool
5.0
1 rating
- 5 stars 1
- 4 stars 0
- 3 stars 0
- 2 stars 0
- 1 star 0
Clear instructions
Find steps, examples and limitations below.
Use online
Open the tool in a supported web browser.
Free to use
No sign-up required. Tool-specific limits may apply.
How to use the Amortization Calculator
Build a month-by-month loan amortization schedule with extra payments.
- 1 Enter the loan amount, rate and term.
- 2 Add an optional extra monthly payment and the first payment date.
- 3 Read the payment, payoff date and the full schedule.
Example and practical tips
Adding 200 a month to a 250,000 30-year loan at 6.5% saves over 90,000 in interest and pays it off years early.
Frequently asked questions
Why is most of the early payment interest?
Interest is charged on the remaining balance, which is highest at the start.
Do extra payments always go to principal?
Usually, but confirm with your lender that extra payments reduce the principal.
Practical guides
-
How to Use Amortization Calculator
Build a month-by-month loan amortization schedule with dates, principal, interest and balance, and see how extra payments cut interest and time.
Report an issue
Something broken or not quite right? Tell us and we will look into it.