Loan Payoff Calculator
Enter your loan balance, interest rate, and monthly payment to find out how many months until you're debt-free. This calculator also shows the total interest you'll pay along the way.
How it works
This calculator solves for the number of payments needed to clear your balance using the standard amortization formula. Each month, interest accrues on the remaining balance at the monthly rate (annual rate ÷ 12), and your payment first covers that interest, with the rest reducing principal.
The number of months n is found with n = -ln(1 - (B·r)/P) / ln(1 + r), where B is the balance, r is the monthly rate, and P is your monthly payment. We then simulate each month to total the interest paid.
Tips
Even small increases to your monthly payment can dramatically shorten payoff time and cut total interest, since extra dollars go straight to principal.
If your payment is less than or equal to the monthly interest charge, the balance never decreases — make sure your payment comfortably exceeds it.
FAQ
What happens if my payment is too low?
If your monthly payment only covers the interest (or less), the principal never shrinks and the loan is never paid off. The calculator will flag this and show the minimum payment needed just to cover interest.
Does this account for extra one-time payments?
No, this tool assumes a fixed, consistent monthly payment. Any extra lump-sum payments would reduce both the payoff time and total interest beyond what's shown here.
Why is the final payment sometimes smaller?
The last payment is usually less than your regular amount because only the remaining balance plus its final interest is due. The calculator rounds up to whole months and adjusts the totals accordingly.