The Excel COUPNUM Function

Related Function:

Function Description

The Excel Coupnum function calculates the number of coupons payable, between a security's settlement date and maturity date, rounded up to the nearest whole coupon.

The syntax of the function is:

COUPNUM( settlement, maturity, frequency, [basis] )

Where the arguments are as follows:

settlement-The settlement date of the security.
maturity-The maturity date of the security.

An integer, representing the number of coupon payments per year. This must have the value 1, 2, or 4, meaning:


An optional integer argument that specifies the day count basis to be used.

This must be one of the following values:

BasisDay Count Basis
0 (or omitted)US (NASD) 30/360
4European 30/360
The financial day count basis rules are explained on the Wikipedia Day Count Convention page

Note that the settlement and maturity dates should be input as either:


Warning: If you attempt to input these dates as text, there is a chance that Excel may misinterpret them due to different date systems, or date interpretation settings on your computer.

Excel Coupnum Function Example

Cell A3 of the spreadsheet below shows the Excel Coupnum function, used to calculate the number of coupon payments for a security that uses the US (NASD) 30/360 day count basis, has the settlement date 01-Jan-2011, the maturity date 25-Oct-2012, and 4 coupon payments per year.

3=COUPNUM( A1, A2, 4 )

In the above example:

For further details and examples of the Excel Coupnum function, see the Microsoft Office website.

Coupnum Function Errors

If you get an error from the Excel Coupnum Function, this is likely to be one of the following:

Common Errors

Occurs if either:

  • The supplied settlement date is ≥ maturity date;
  • The supplied frequency argument is a number that is not equal to 1, 2 or 4;
  • The supplied [basis] argument is a number that is not equal to 0, 1, 2, 3 or 4.

Occurs if either:

  • The supplied settlement or the supplied maturity dates are not a valid Excel dates;
  • Any of the supplied arguments are non-numeric.