Instructions: Type in known values, then press Calculate for the desired unknown.
Present Value (pv)
Future Value (fv)
Number of Payment Periods (np)
Payment Amount (pmt)
Interest Rate Per Period (ir) %

Remember to use negative values for owed balances and money paid to the account, positive values for balances in your favor and money withdrawn from the account.
Also, enter the interest rate per period, not per year. If you are making monthly payments and have an annual interest rate, divide the annual rate by 12 (and see my note at the bottom of this page). Thus, an 8% annual rate would be entered as 8/12 or .666667... (either form is accepted). All fields must be filled in, use zeros if necessary.

The variables used are: