The Excel COMPLEX Function

Complex Numbers

Within the world of complex numbers, the 'imaginary' value, i is used to represent the square root of -1.

A Complex Number is composed of a real number combined with an imaginary number.

E.g. The complex number, z, is written as

z   =   5 + 2i

Basic Description

The Excel Complex function takes two arguments, representing the real and the imaginary coefficients of a complex number, and from these, creates a complex number.

The format of the function is:

COMPLEX( real_num, i_num, [suffix] )

where the arguments are as shown in the table below:

real_num-The real component of the complex number.
i_num-The imaginary component of the complex number.

An optional text argument, equal to "i" or "j" that specifies the suffix to be used.

I.e. whether the imaginary number is written in the style 5+2i or 5+2j.

If omitted, the [suffix] argument takes on the default value "i".

Excel Complex Function Examples

In the examples below, the Complex function is used to create different complex numbers in Excel.

1=COMPLEX( 5, 2 )
2=COMPLEX( 5, -9 )
3=COMPLEX( -1, 2, "j" )
4=COMPLEX( 10, -5, "i" )
5=COMPLEX( 0, 5 )
6=COMPLEX( 3, 0 )

Further examples of the Excel Complex function can be found on the Microsoft Office website.

Complex Function Error

If you get an error from your Excel Complex function this is likely to be the #VALUE! error:

Common Error

Occurs if either:

  • One or both of the supplied real_num or i_num arguments are non-numeric
  • The supplied [suffix] argument is something other than "i" or "j".