IPMT

Description: Returns the interest payment for a period of time based on an investment with periodic constant payments and a constant interest rate. For a more complete description of the arguments in IPMT and for more information about annuity functions, see the PV function.

Syntax: IPMT(Rate, Per, Nper, PV, [FV], [Type])

Rate is the interest rate per period.
Per is the period for which you want to find the interest and must be in the range 1 to Nper.
Nper is the total number of payment periods in an annuity.
PV is the present value, or the lump-sum amount that a series of future payments is worth right now.
FV is the future value, or a cash balance you want to attain after the last payment is made. If FV is omitted, it is assumed to be 0 (the future value of a loan, for example, is 0).
Type is the number 0 or 1 and indicates when payments are due. If Type is omitted, it is assumed to be 0.

Set type equal to	If payments are due
0 or omitted	At the end of the period
1	At the beginning of the period

Remarks:

Make sure that you are consistent about the units you use for specifying Rate and Nper. If you make monthly payments on a four-year loan at 12 percent annual interest, 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, cash you pay out, such as deposits to savings, is represented by negative numbers; cash you receive, such as dividend checks, is represented by positive numbers.

Example:

Interest due in the first month for a loan with the terms above

IPMT(.10/12, 1*3, 3, 8000,0,0) = -22.41

Interest due in the last year for a loan with the terms above, where payments are made yearly

IPMT(.10, 3, 3, 8000,0,0) = -292.45