Calculator Inputs
Example Data Table
| Loan Amount | Rate | Term | Frequency | Custom Payment | Extra Payment | Payments Made | Estimated Balance |
|---|---|---|---|---|---|---|---|
| $250,000.00 | 6.50% | 30 years | Monthly | Auto | $100.00 | 60 | Varies by exact schedule and payment date |
| $40,000.00 | 7.25% | 5 years | Monthly | $900.00 | $50.00 | 18 | Lower than a standard schedule because of extra payments |
| $12,000.00 | 0.00% | 2 years | Monthly | Auto | $0.00 | 6 | Exactly reduced by the principal already repaid |
Formula Used
r = annual interest rate / payments per year
A = P × [ r / (1 - (1 + r)^(-N)) ]where
P is the original principal and N is the total number of payment periods.
Bₙ = P(1 + r)^n - A × [ ((1 + r)^n - 1) / r ]
When you add extra payments or enter a custom payment amount, this calculator uses a period-by-period amortization simulation. That method is more reliable because each payment changes later interest charges and may shorten the payoff date.
How to Use This Calculator
- Enter the original loan amount and annual interest rate.
- Select the payment frequency: monthly, biweekly, or weekly.
- Add the full loan term using years and any extra months.
- Leave custom payment blank for the normal amortized payment, or enter your own amount.
- Add any recurring extra payment you plan to make each period.
- Enter how many payments you have already completed.
- Choose the first payment date to build the schedule correctly.
- Click the button to view the current balance, payoff progress, graph, and amortization table.
Frequently Asked Questions
1) What does loan balance mean?
Loan balance is the unpaid principal remaining on your debt after previous payments. It excludes future interest that has not yet been charged.
2) Is loan balance the same as payoff amount?
Not always. Payoff amount may include accrued daily interest, unpaid fees, or a payoff quote valid through a certain date. Balance is the core remaining principal used for schedule tracking.
3) How do extra payments affect the balance?
Extra payment reduces principal faster, which lowers future interest charges and may shorten the loan term. Even small recurring extras can create noticeable savings over time.
4) Can I enter my own payment amount?
Yes. Leave the payment field blank to auto-calculate the standard amount, or enter your own value to model accelerated or slower repayment.
5) Why might my balance differ from my lender statement?
Your lender may use a different compounding convention, timing cutoff, escrow items, or pending transactions. Use this tool for planning, then confirm final figures with the lender’s current statement or payoff quote.
6) Does payment frequency matter?
Yes. Monthly, biweekly, and weekly schedules change the periodic rate, number of payments, and date pattern. More frequent payments can reduce balance faster when total yearly payments increase.
7) What happens when the interest rate is zero?
With zero interest, every payment goes directly toward principal. The calculator simply divides the remaining balance across the remaining payment periods.
8) Can I export the results?
Yes. Use the CSV button for spreadsheet analysis and the PDF button for a printable report containing your summary and full amortization schedule.