$12,000 at 8% with $350.00/mo
- Total interest
- $1,669.76
- Total paid
- $13,669.76
- Base monthly payment
- $300.00
- Extra monthly payment
- $50.00
Real balances can change with fees, payment timing, minimum-payment rules, collections, or new charges.
Repayment Calculator
Use this free repayment calculator to estimate how long a balance may take to repay and how much interest may be paid from rate, payment, and optional extra payment.
Formula steps Estimate limits shown Examples included Private history
Formula steps
- Convert the annual interest rate to a monthly rate.
- Add monthly interest to the remaining balance.
- Subtract the base payment plus any extra monthly amount.
- Repeat until the balance reaches zero, then add up interest and total paid.
How to use the repayment calculator
- Enter the requested dollar amounts, rates, terms, tax settings, or contribution details.
- Use rates as percentages, such as 6.5 for 6.5%, and check whether a field asks for a monthly or annual amount.
- Press the calculate button to see the answer, supporting metrics, and formula steps.
- Use the result as a planning estimate only, then copy it if the assumptions look right.
Common uses
Estimate how long a balance may take to repay.
Test whether a payment is enough to reduce principal.
Compare repayment with and without extra monthly payment.
Create a simple repayment plan for a fixed balance.
Examples
Estimated repayment time
Short payoff estimate
Baseline repayment estimate
Frequently asked questions
Plain-language answers about when to use the estimate, what your numbers mean, what is left out, and how privacy works.
When should I use the Repayment Calculator?
Use it for early planning and side-by-side comparisons, especially for tasks like these: Estimate how long a balance may take to repay. Test whether a payment is enough to reduce principal. Treat the answer as a planning estimate, not a final quote.
What is the Repayment Calculator doing with my numbers?
In plain language: The calculator adds monthly interest, subtracts the regular and extra monthly payment, and repeats until the balance is paid off. If the result seems too high or too low, first check whether each field expects a monthly amount, annual amount, dollar value, or percent.
What does this estimate leave out?
This is a general fixed-rate repayment estimate. It does not include payment pauses, deferment, fees, changing rates, income-based plans, or provider-specific rules. Real finance decisions can also depend on fees, timing, local rules, credit details, and provider-specific terms.
Does the site save my finance inputs?
No. The calculator runs in your browser tab. Recent answers stay only on the page while you use it, and they are not sent to a server.