The calci%yr function calculates the anual interest rate, as follows:

->a

This calculation is done using an iterative approach. The other values used in the calculation must be reasonable in order to get a reasonable result.

The number of payments per year (stopyr) must be set before any time value of money calculations can be done. The default is monthly payments. Four out of five of the following must be set before calculating the fifth value: future value (stofv), annual interest rate (stoi%yr), number of payments (ston), payment value (stopmt), and present value (stopv).