Related Function:
The ISPMT function calculates the interest paid, during a specific period of a loan or investment.
Syntax
=ISPMT(rate,per,nper,pv)
Arguments
Argument  Description 

rate  The interest rate – per period 
per  The period for which you want to find the interest, and must be between 1 and nper 
nper  The total number of payment periods for the investment 
pv  The present value of the investment. For a loan, pv is the loan amount 
Examples
A  B  C  D  

1  Data  
2  10%  Annual interest rate  
3  3  Loan term – years  
4  $800,000  Amount of loan  
5  
6  Formula  Result  Notes  
7  =ISPMT(A2/12,1,A3/12,A5)  $64,814.80  Interest paid for the first monthly payment of a loan with the above terms  
8  =ISPMT(A2,1,A3,A4)  $533,333.00  Interest paid in the first year of a loan with the above terms 
Note: In the above example, the payments are made monthly, so
 the annual interest rate of 10% had to be converted into a monthly rate (=10%/12), and
 the number of years had to be converted into months (=3*12)
Cash Flow Convention: In line with general cash flow conventions, outgoing payments are represented by negative numbers and incoming payments are represented by positive numbers.
Common Function Error(s)
Problem  What went wrong  

#VALUE!  Occurs if any of the supplied arguments are not recognized as numeric values  
Result is much higher or much lower than expected  Usually occurs due to failure to convert the rate or the nper to months or quarters, i.e.:
