Repayment Calculator
Enter what you owe, the annual interest rate and the monthly payment you can make. The calculator counts the months until the debt is repaid. It also shows the last payment, which covers only what is left, the total interest and the total paid.
How to use the Repayment Calculator
- Enter your numbers in the Repayment Calculator above.
- Press the Calculate button to see the result.
- To try other numbers, change any value and press the button again.
How the months are counted
Interest = balance × rate ÷ 12, rounded to the cent · · · New balance = balance + interest − payment
The calculator runs the loan month by month, the way a lender's statement does. Each month it adds the balance times the annual rate ÷ 12, rounded to the cent, and then takes off your payment. When the balance plus that month's interest is no more than the payment, the last month pays exactly that and the count stops. At 0% no interest is added. The months are then the balance ÷ the payment, rounded up, and the last payment is what remains.
Worked example
$10,000 at 8% with a $250 monthly payment takes 47 months. That is 46 payments of $250 and a last one of $169.70. The interest comes to $1,669.70 and the total paid to $11,669.70. At $500 a month the same loan takes 22 months and $768.73 in interest. At 0%, $8,000 paid at $300 a month takes 27 months, and the last payment is $200.
Frequently asked questions
What if my payment does not cover the interest?
If the payment is no more than the first month's interest, the balance never goes down and the debt is never repaid. The calculator then shows that first month's interest instead of a result. On $8,000 at 12% it is $80.00, so the payment has to be more than $80.00.
Does this work for any type of debt?
It works for any debt with a fixed rate and the same payment every month, such as a personal loan, a car loan or a credit card you no longer use. A variable rate, or a minimum payment that falls as the balance falls, needs a different calculation. For a card you can also use the credit cards payoff calculator, which adds the payoff date and a payment schedule.
How much does a larger payment save?
Run the calculator once for each payment and compare. On $10,000 at 8%, $250 a month takes 47 months and costs $1,669.70 in interest. $300 a month takes 38 months and costs $1,346.98, and $500 a month takes 22 months and costs $768.73.