Calculates the interest paid during a specific period of an investment.
Syntax
ISPMT(rate,per,nper,pv)
Rate is the interest rate for the investment.
Per is the period for which you want to find the interest, and must be between 1 and nper.
Nper is the total number of payment periods for the investment.
Pv is the present value of the investment. For a loan, pv is the loan amount.
Remarks

Make sure that you are consistent about the units you use for specifying rate and nper. If you make monthly payments on a fouryear loan at an annual interest rate of 12 percent, use 12%/12 for rate and 4*12 for nper. If you make annual payments on the same loan, use 12% for rate and 4 for nper.

For all the arguments, the cash you pay out, such as deposits to savings or other withdrawals, is represented by negative numbers; the cash you receive, such as dividend checks and other deposits, is represented by positive numbers.

For additional information about financial functions, see the PV function.
Examples
In the first example, the interest rate is divided by 12 to get a monthly rate. The years the money is paid out is multiplied by 12 to get the number of payments.
R ate 
Per 
Nper 
PV 
Formula 
Description (Result) 
10% 
1 
3 
8000000 
=ISPMT([Rate]/12,[Per],[Nper]*12,[PV]) 
Interest paid for the first monthly payment of a loan with the specified arguments (64814.8) 
10% 
1 
3 
8000000 
=ISPMT([Rate],1,[Nper],[PV]) 
Interest paid in the first year of a loan with the specified arguments (533333) 