Loan Payoff Calculator

Enter what you owe today, the APR and the fixed amount you will pay each month. The calculator finds how many monthly payments it takes to clear the balance, with interest charged each month at APR ÷ 12:

months = −ln(1 − r × balance ÷ payment) ÷ ln(1 + r), rounded up to a whole month.

With the defaults ($12,000 at 9%, paying $350 a month) that is 40 payments, shown as 3 yr 4 mo.

If your payment doesn't cover the first month's interest, the balance can never fall, and the calculator says so. On the default loan the interest is $90 a month, so a $90 payment shows "Never". Just $1 more changes the answer, but only to 50 years 4 months, because almost every dollar still goes to interest.

One input it can't handle is a 0% APR: the time shows as "NaN yr NaN mo". For an interest-free balance, divide the balance by the payment and round up.

The total-paid figure is the monthly payment × the number of months, so it counts the final payment as a full one. In reality the last payment is only what is left. On the default loan the 40th payment is about $273.91, not $350, so the interest you actually pay is about $1,923.91, not the $2,000 shown.

The payoff times are right. The interest column can overstate by up to one payment, which is why $350 and $400 both show $2,000. When you compare two payment levels, compare the payoff times, or use the right-hand column.

The calculator starts from a payment. If you start from a date instead, find the payment with the personal loan calculator: enter the balance, the APR and the time you have left. To clear $12,000 at 9% in 2 years, that gives $548.22 a month. Enter $548.22 here and the payoff time reads 2 yr 0 mo.

The same check works for a loan you are already repaying on schedule. Enter the current balance, the rate and your regular payment, and the payoff time should match the months left on your statement. A car loan with $18,000 left at 6.9% and a $425 payment shows 4 yr 1 mo. If the answer is longer than your schedule, your payment may not be what you think, or fees are being added.

Keep your payment the same and change only the APR to the new offer's. On the default loan, refinancing $12,000 to 6.5% at $350 a month shows 3 yr 3 mo instead of 3 yr 4 mo. On a short loan a lower rate saves more money than time: allowing for the smaller final payment, the total you repay falls from about $13,923.91 to $13,310.79.

Fees change the picture. If the new lender adds a $300 fee to the balance, enter $12,300: the payoff is back to 3 yr 4 mo, and the saving shrinks to about $243.

For this comparison, rely on the payoff time and the corrected totals, not the total-paid line. The calculator shows $14,000 paid both for the current loan and for the refinance with the fee, because each counts 40 full payments of $350.