Documentation/How Tos/Calc: CUMIPMT ADD function

CUMIPMT_ADD

Returns the total interest paid on a loan in specified periodic payments.

This function is only available if the Analysis AddIn is installed.

Syntax:

CUMIPMT_ADD(rate; numperiods; presentvalue; start; end; type)

rate: the interest rate per period.

numperiods: the total number of payment periods in the term.

presentvalue: the initial sum borrowed.

start: the first period to include. Periods are numbered beginning with 1.

end: the last period to include.

type: when payments are made:

0 - at the end of each period.

1 - at the start of each period (including a payment at the start of the term).

With a fixed rate loan, where you make a constant payment each period to pay off the loan over the term, some of each period payment is interest on the outstanding capital, and some is a repayment of capital. Over time (as you pay off capital), the interest becomes less and the capital repayment becomes more.

IPMT returns the interest in the payment of a specified period. PPMT returns the capital repaid in the payment of that period. Together they add up to the actual payment, given by PMT.

CUMIPMT_ADD returns the total interest paid during the periods start to end inclusive - that is, the sum of IPMT over that time.

Example:

CUMIPMT_ADD(5.5%/12; 12*2; 5000; 4; 6; 0)

returns approximately -57.80. You took out a 2 year loan of 5000 currency units at a yearly interest rate of 5.5%, making monthly payments at the end of the month. The interest you pay in the 4th-6th months inclusive is 57.80 currency units. It is given as negative because you pay it.

Issues:

• CUMIPMT_ADD is compatible with Excel; it does not apply currency formatting and thus can show fractional amounts, for example 57.5412415... The * CUMIPMT function formats the result as currency if the cell has default formatting, and thus shows a real (rounded) currency amount, for example $57.54; the amount may still be fractional - this just affects the display.
• According to the forthcoming ODFF standard, this function is to be renamed * CUMIPMT, and the existing CUMIPMT removed.
• In contrast to PMT, IMPT, PPMT, this function has no futurevalue parameter.