Manuals/calci/IPMT

IPMT(r,pr,np,pv,fv,type)

Description

This function gives amount of interest for a particular time, according to the periodic, fixed payments and fixed interest rate.
This function can be used to calculate the payments for a loan or the future value of an investment.
In $IPMT(r,pr,np,pv,fv,type)$ , where $r$ is the rate of interest for a year
$pr$ is the period for which the interest payment is to be calculated. It must be a value between $1$ and $np$ .
$np$ is the total number of periods over which the loan or investment is to be paid.
$pv$ is the present value of the loan.
$fv$ is the future value of the loan, at the end of $np$ payment.
$type$ is the number $0$ or $1$ .
When type value is $0$ means the payment is made at the end of the period and type value is $1$ means the payment is made at the beginning of the period
Here the arguments $fv$ and $type$ are optional.
Suppose we omit the value of $fv$ , then it will consider the value as $0$ .
Also when we are not giving the $type$ value, the default value is $0$ .
Suppose we calculate the monthly payments instead of annual payment, for the argument $r$ we have to divide by $12$ and the $np$ value we have multiply with $12$ .
For e.g. The monthly payments on a 5 year loan at 10% annual interest, we have to give the arguments $r$ and $np$ as 10%/12 for $r$ and 5*12 for $np$ .
This function will give result as error when

Any one of the argument is non-numeric
 $pr<0$  or  $pr>np$

1. Calculate the interest payment during half yearly 1 and 2 of a loan for 50,000, that is to be reduced to 10,000 over a period of 3 years, by a series of constant half-yearly payments.
Interest is charged at a rate of 4.5% per year and the payment is made at the beginning of each half year.
IPMT(4.5%/2,3,2*2,50000,10000,1)= -480.666
1. The interest payment for a $55000 investment that earns 7.50% annually for 15 years.
The interest payment is calculated for the 5th year and payments are due at the end of each year.

IPMT(7.5%/1, 5, 15*1, 55000)=-3418.570