PAYMENT( )
Returns the periodic amount required to repay a debt.
Syntax
PAYMENT(<principal expN>, <interest expN>, <term expN>)
<principal expN>
The original amount to be repaid over time.
<interest expN>
The interest rate per period expressed as a positive decimal number. Specify the interest rate in the same time increment as the term.
<term expN>
The number of payments. Specify the term in the same time increment as the interest.
Description
Use PAYMENT( ) to calculate the periodic amount (payment) required to repay a loan or investment of <principal expN> amount in <term expN> payments. PAYMENT( ) returns a number based on a fixed interest rate compounding over a fixed length of time.
If <principal expN> is positive, PAYMENT( ) returns a positive number.
If <principal expN> is negative, PAYMENT( ) returns a negative number.
Express the interest rate as a decimal. For example, if the annual interest rate is 9.5%, <interest expN> is .095 (9.5/100) for payments made annually.
Express <interest expN> and <term expN> in the same time increment. For example, if the payments are monthly, express the interest rate per month, and the number of payments in months. You would express an annual interest rate of 9.5%, for example, as .095/12, which is 9.5/100 divided by 12 months.
The formula dBASE Plus uses to calculate PAYMENT( ) is as follows:
where int = rate/100
For the monthly payment required to repay a principal amount of $16860.68 in five years, at 9% interest, the formula expressed as a dBL expression looks like this:
? PAYMENT(16860.68,.09/12,60) // Returns 350.00
nTemp = (1 + .09/12)^60
? 16860.68*(.09/12*nTemp)/(nTemp-1) // Returns 350.00
Use SET DECIMALS to set the number of decimal places PAYMENT( ) displays.