Payment Calculator
Solve a loan two ways: set a fixed term to get the monthly payment, or set a fixed monthly payment to see how long the payoff takes.
What do you know?
How to use this calculator
1. Choose what you already know
Switch to Fixed term if you know how long you want the loan to last, or Fixed payments if you know how much you can afford to pay each month.
2. Enter the amount and rate
Type the loan amount and the annual interest rate as a percentage. The rate is divided by 12 to get the monthly figure used in the math.
3. Add the term or the payment
In fixed-term mode, enter the number of years. In fixed-payment mode, enter the monthly amount — it must be larger than one month of interest, or the loan would never be repaid.
4. Compare the outcomes
The big number is either your required payment or your payoff time. The cards show the total repaid and the total interest. To explore deferred or bond-style loans instead, use the Loan Calculator.
About payment calculations
What is the difference between fixed term and fixed payments?
Fixed term starts from a payoff length you choose and tells you the monthly payment needed to clear the loan in that time. Fixed payments starts from the amount you can pay each month and tells you how many months it will take to be debt-free.
Why can a monthly payment be too low?
If your monthly payment is smaller than the interest charged that month, the balance grows instead of shrinking and the loan never clears. The payment must be greater than the loan amount times the monthly rate for the balance to fall.
How is payoff time found?
From a fixed payment M, the number of months is n = −ln(1 − P × i / M) / ln(1 + i), where P is the balance and i is the monthly rate. We then split that into whole years and months.