How the payoff time is worked out
Each month interest is charged at the note rate divided by 12 and your payment comes off. The calculator counts the payments, rounding up, with a smaller final payment.
Worked example
A $15,000 balance at 9%, paying $400 a month from December 1, 2026, takes 45 payments, the last of $79.09, on August 1, 2030. Interest totals $2,679.09.
$1,000 at 12% paid at $100 a month takes 11 payments with $58.98 of interest.
Pay it off faster
Extra principal payments shorten the loan and save interest. Check whether your loan has a prepayment penalty: it usually applies only when you pay off the whole loan early, and it can cut into what you save.
To see how extra payments change your payoff date, use the US loan payoff calculator .
What this calculator assumes
A fixed note rate and the same payment each month. On a simple interest loan, paying early or late in the month changes the interest slightly.
Borrowing in the UK?
The country choices above the inputs open separate local pages. UK lenders quote an APR, which already includes monthly compounding. Choosing United Kingdom opens that page and resets the inputs; amounts are not converted.
For the UK version, use the UK how long to repay a loan calculator in pounds.
Inputs for the US how long to pay off a loan calculator
Amount you owe
The balance now, in US dollars.
Interest rate
The yearly note rate.
Monthly payment
What you'll pay each month.
First payment date
When you'll make the next payment.
CALCULATOR QUESTIONS
US how long to pay off a loan calculator questions
How do I calculate how long to pay off a loan?
Use n = −ln(1 − r × balance ÷ payment) ÷ ln(1 + r), where r is the note rate ÷ 12, and round up.
How long to pay off $15,000 at $400 a month?
At 9%, 45 payments, or 3 years and 9 months.
Why does my loan never get paid off?
Your payment is less than or equal to the monthly interest. Pay more each month.
Do extra payments go to principal?
Usually, but ask your lender to apply them to principal rather than future payments.