About the Loan Repayment Calculator
See how long it takes to repay a loan with a fixed monthly payment you choose, and the total interest you’ll pay.
Also known as: how long to pay off loan, repayment period, loan payoff time.
How to use this calculator
- Enter loan balance, interest rate, monthly payment.
- The result updates instantly as you type — press Calculate (or Enter) at any time.
- Review the breakdown shown under the main result.
- Use Copy result or Share to save the answer or send a link with your inputs.
Formula
n = −ln(1 − rB/P) / ln(1 + r)
Worked example
Using the values pre-filled in the calculator above:
- Loan balance = 20,000
- Interest rate = 9 %
- Monthly payment = 500
the calculator returns:
- Time to repay: 4 yr 0 mo
- Total interest: 3,867.75
- Total paid: 23,867.75