Repayment Calculator
See your full loan repayment schedule with principal vs interest breakdown and your exact payoff date.
| Year | Principal | Interest | Total Paid | Balance |
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Generate a full year-by-year repayment schedule for any fixed-rate loan, showing your monthly payment, the principal-versus-interest split, and your exact payoff date.
How Repayment Calculator Works
The monthly payment is found using the standard amortization formula: payment = loan × r ÷ [1 − (1 + r)⁻ⁿ], where r is the annual rate divided by 12 and n is the loan term in years multiplied by 12. Each month afterward, interest is charged on the remaining balance, and the rest of the payment reduces principal — the year-by-year table and bar chart aggregate these monthly splits so you can see how the balance of interest versus principal shifts as the loan matures.
If you add an extra monthly payment, it is added on top of the required payment and applied straight to principal, since interest for that month is already covered. The calculator runs the full schedule twice — once with and once without the extra amount — so it can report how much interest that extra payment actually saves.
Entering a start date lets the calculator count forward by the number of months it takes to reach a zero balance, converting that into an actual payoff month and year rather than just a raw month count.
See It In Action
Who Uses Repayment Calculator and Why
- Generating a full year-by-year repayment schedule for a fixed-rate loan, including an exact projected payoff date.
- Seeing how much interest a fixed extra monthly payment saves compared to the required payment alone.
- Projecting a payoff date from today's date forward for a loan that's already partway through repayment.
- Visualizing how the principal-versus-interest split shifts across the life of a loan using the bar chart and table.
Mistakes to Avoid
- Entering the original loan amount instead of your current outstanding balance for a loan already in progress — for an in-progress loan, enter today's actual balance and set the start date to today so the schedule projects forward from where you really stand.
- Assuming the extra payment is split between interest and principal — it isn't; required interest for the month is deducted first from the total payment, and everything remaining, including the extra amount, goes straight to reducing principal.
- Overlooking that the start date only affects the payoff-date label, not the payment amount — changing it doesn't alter the underlying interest or principal math, only how the schedule's months are converted to calendar dates.
Tips for Best Results
- For a loan you're already partway through, enter your current outstanding balance rather than the original loan amount, and set the start date to today for an accurate forward-looking schedule.
- Compare the schedule with and without an extra monthly payment to see the concrete payoff-date difference, not just the interest-savings dollar figure.
Fixing Common Problems
The projected payoff date doesn't match what I expect for a loan I've already been paying for a while. — Make sure you entered your current outstanding balance (not the original loan amount) as the loan amount, and set the start date to today — the schedule projects forward from those two inputs, not from the loan's original origination date.
Terms Explained
Payoff date: The specific calendar month and year the loan balance is projected to reach zero, calculated by adding the schedule's total months to the entered start date.
Year-by-year schedule: A table aggregating each year's payments into principal paid, interest paid, and remaining balance.