PHP Software Source Code Financial Library Simple Interest Equation

AJ PHP Software Source Code Financial Library
Simple Interest

number simple_interest ( number, number, number )

Description:

simple_interest returns the interest earned given principal, number of periods and interest rate.

simple interest = principal X number of periods X interest rate

Source Code:

function simple_interest ($principal, $number_of_periods, $interest_rate)
{
//variable and initializations
$the_result = 0.0;

//calculate simple interest
$the_result = $principal * $number_of_periods * $interest_rate;

//return the value
return $the_result;
}

Example:

<?
include ("ajfinancial.php");

$principal = 100.00; //100 dollars
$periods = 10; //10 periods
$interest_rate = 0.06; //6 percent interest

$interest = simple_interest($principal, $periods, $interest_rate);

echo "principal = $principal<br>";
echo "periods = $periods<br>";
echo "interest_rate = $interest_rate<br>";
echo "interest = $interest<br>";
?>

Run Example

percent interest rate	percent interest rate
simple interest	simple interest
future worth SPCAF	future worth single payment compound amount factor SPCAF
present worth SPPWF	present worth sing payment present worth factor SPPWF

References - Books:

Leland T. Blank and Anthony J. Tarquin.r. 1989. Engineering Economy. McGraw-Hill, Inc.