Repayment Calculator
Current Loan Balance
Repayment Summary
| Monthly Payment | — |
|---|---|
| Payoff Timeline | — |
| Total Interest | — |
| Total Repayment | — |
How to Use This Repayment Calculator
You are not shopping for a new loan—you are already in one. The servicer letter says balance and rate, but not always what happens if you keep paying the minimum. I built this for existing debt: enter what you owe today, how many months are left, and see the full payoff path.
- Enter current loan balance. The principal remaining on your statement today.
- Enter interest rate. Your annual APR as shown on the loan agreement or servicer portal.
- Enter remaining term in months. Not years—use the exact months left (e.g. 48).
- Press Calculate. Review monthly payment, payoff timeline, total interest, total repayment, and the month-by-month schedule.
Planning a new loan instead? Start with the Loan Calculator. Want to see how extra payments change payoff order across multiple debts? Try the Debt Payoff Calculator.
Repayment Formulas and Practical Applications
Repayment math assumes you continue level monthly payments until the balance hits zero. The schedule shows how each payment splits between interest and principal as the balance declines.
Monthly payment on remaining balance
M = B × [ i(1 + i)ⁿ ] / [ (1 + i)ⁿ − 1 ]
Where B is current balance, i is monthly rate, and n is remaining months. A $18,500 balance at 8.25% with 48 months left needs about $454/month.
Interest portion each month
Interestk = Balancek−1 × i
Principalk = M − Interestk
Month one on that loan accrues roughly $127 in interest; by month 48, interest is only a few dollars because the balance is nearly gone.
Why months, not years
Real loans rarely have tidy year counts left. Entering 47 or 53 months directly avoids rounding a partial year into a wrong payment.
Frequently Asked Questions
What inputs does the repayment calculator need?
Enter your current loan balance, annual interest rate, and remaining term in months. The calculator returns the level monthly payment to pay off on schedule.
How is this different from the Loan Calculator?
The Repayment Calculator is for loans you already hold—it uses current balance and remaining months. The Loan Calculator models a new loan from original amount and term in years.
Does the repayment schedule show every month?
Yes. After calculating, a month-by-month table lists payment, principal, interest, and remaining balance until payoff.
What if I make extra payments?
This tool assumes fixed scheduled payments with no prepayments. Extra principal payments would shorten the timeline and reduce total interest.
Why is the term entered in months instead of years?
Existing loans often have odd remaining terms—say 47 months left. Entering months directly avoids rounding errors from converting years.