ISPMT

ISPMT(rate, per, nper, pv)

Returns the interest paid for a given period in a series of equal cash flows at regular intervals (incorrectly).

rate	The fixed interest rate per period.
per	The period for which you want to find the interest (starting at 0)
nper	The total number of payments.
pv	The present value.

REMARKS

* This function is only available for backwards compatibility and should not be used.
* This function uses an incorrect formula to calculate the interest and was replaced with IPMT.
* This function assumes that principle payments are constant but interest varies which means that the total payment varies.
* This function assumes the amount of principal paid back every period is constant. This assumption is incorrect.
* This function assumes the total amount repaid every period varies. This assumption is incorrect.
* The IPMT function assumes that total payments are constant meaning both the principle payment and the interest vary.
* The "per" must be in the range 0 to ('nper' - 1).
* This function has been available since Excel 1997.
* For the Microsoft documentation refer to support.microsoft.com
* For the Google documentation refer to support.google.com

	A
1	=ISPMT(10%/12, 0, 5*12, 10000) = ($83.33)
2	=ISPMT(5%/12, 0, 12*15, 50000) = ($208.33)
3	=ISPMT(0.1/12, 0, 36, 8000) = ($66.67)
4	=ISPMT(10%/12, 1, 5*12, 10000) = ($81.94)
5	=ISPMT(10%/12, 2, 5*12, 10000) = ($80.56)

1 - How much interest is paid back in the first month if I borrow £10,000 for 5 years at an annual interest rate of 10%.
2 - How much interest is paid back in the first month if I borrow £50,000 for 15 years at an annual interest rate of 5%.
3 - How much interest is paid back in the first month if I borrow £8,000 for 3 years at an annual interest rate of 10%.
4 - How much interest is paid back in the second month if I borrow £10,000 for 5 years at an annual interest rate of 10%.
Incorrect. The correct value using IPMT is ($82.26).
5 - How much interest is paid back in the third month if I borrow £10,000 for 5 years at an annual interest rate of 10%.
Incorrect. The correct value using IPMT is ($81.17).