The Financial Calculator is used to calculate compound interest. It provides a way of entering four of the five parameters of a compound interest calculation and then calculating the remaining figure.
The calculator is split into two panes. The left pane has five fields with a Calculate button and a Clear button. The Calculate button is used to select the figure to calculate. The Clear button is used to clear any amount in the field.
Payment Periods: This field is used to select the number of payments you wish to use in the calculation.
Interest Rate: This field is used for the interest rate percentage.
Present Value: This field usually contains the amount you have borrowed. It is the base amount you wish to compound.
Periodic Payment: This field contains the amount that is the payment for the period selected (IE monthly, weekly, etc). If it is for repaying a loan it should be a negative number.
Future Value: This field contains the final value at the end of the periods above. If we are repaying a loan in full it would be '0'.
The right pane contains buttons to select what sort of payments and compounding is used for the left pane calculations.
Compounding: This button allows you to select the interval used if the Discrete Compounding button is selected.
Payments: This button allows you to select the interval used for the Payment Periods field.
End of Period Payments: Use this button if the payment is at the end of the period.
Beginning of Period Payments: Use this button if the payment is at the beginning of the period.
Discrete Compounding: This button is used where interest is charged at a discrete interval defined by the Compounding button above.
Continuous Compounding: This button is used when the interest is charged continuously.
Payment Total: This field shows the total amount paid.
Examples of using the Financial Calculator are given in the Tutorial and Concepts Guide. GnuCash Tutorial and Concepts Guide's Chapter on Loans