The Excel COMPLEX function builds a complex number from real and imaginary coefficients — part of Excel’s complex-number toolkit for engineering and signal analysis.
Syntax
| Argument | Description | |
|---|---|---|
real_num | Required | The real coefficient. |
i_num | Required | The imaginary coefficient. |
suffix | Optional | "i" (default) or "j". |
How to use it
COMPLEX builds a complex number from real and imaginary coefficients. Complex numbers are written as text like "3+4i" (or with a "j" suffix). Build them with COMPLEX and pull the parts back out with IMREAL and IMAGINARY.
All IM functions take and return text. Keep complex numbers as text strings throughout your calculation chain; use IMREAL / IMAGINARY only when you need numeric parts for charts or further math.
Try it: interactive demo
Enter a complex number (a+bi) and see the formula COMPLEX would evaluate.
Practice workbook
Frequently asked questions
How are complex numbers stored in Excel?
Does COMPLEX return text or a number?
Can I mix i and j suffixes?
What if my real or imaginary part is zero?
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