Paying off a personal loan
A $15,000 balance at 7% paid down with $350 a month is fully paid off in 49.4 months, a bit over 4 years.
Loan payoff time calculator
This is an estimate for information only. It is not financial advice and does not replace your loan statement.
Result
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How it works
A loan payment is split between interest on the remaining balance and a reduction of that balance. When the payment barely covers interest, payoff drags on for a very long time; a payment even slightly above that threshold pays it off in a finite, calculable number of months.
The formula solves the standard loan-payment equation for the number of periods instead of for the payment amount.
Formulas used
Number of monthly payments
n = −ln(1 − P × i ÷ M) ÷ ln(1 + i)
- P
- loan balance
- i
- monthly interest rate
- M
- fixed monthly payment
Worked examples
Paying more to finish sooner
The same balance at $500 a month instead takes only 33.1 months and cuts total interest substantially.
Assumptions and limits
- The payment amount and interest rate are constant for the whole payoff period.
- No new charges are added to the balance.
- Interest compounds monthly on the remaining balance.
Frequently asked questions
Why does the calculator say the balance can never be paid off?
If your payment is at or below the interest charged each month, the balance never shrinks — you need a payment above that minimum threshold for payoff to happen at all.
How is this different from a regular loan calculator?
A standard loan calculator solves for the payment given a term. This one flips the question: given a payment you've chosen, it finds the term.
Does paying a little extra each month help a lot?
Yes — extra payments go straight to principal early on, which shortens the remaining term and cuts total interest disproportionately.
Does this work for credit card debt?
Yes, as long as the balance stops growing (no new charges) and the payment and rate stay fixed — real cards often have variable rates and minimums, so treat the result as an estimate.
Updated
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