This guide will explain how to use the IMSUM function in Google Sheets.
When we need to return the sum of a series of complex numbers, cells, or both, we can easily do this using the IMSUM
function in Google Sheets.
Table of Contents
The rules for using the IMSUM
function in Google Sheets are the following:
- The
IMSUM
function allows us to add multiple complex numbers together. - A complex number must be in the format “a+bi” or “a-bi”, where a and b are real numbers and i is the imaginary unit.
- If the given number is not a valid complex number, the
IMSUM
function returns an error. - The sum of two complex numbers is defined as (a+bi) + (c+di) = (a+c) + (b+d)i.
- We can only sum complex numbers if they have the same suffix (i or j).
One of the many Google Sheets functions that let us perform difficult tasks is the IMSUM
function. We can use this to sum multiple complex numbers together. When adding complex numbers, the real and imaginary parts are considered separately.
In this guide, we will provide a step-by-step tutorial on how to use the IMSUM
function in Google Sheets. Additionally, we will explore the syntax and a real example of using the function.
Great! Let’s dive right in.
The Anatomy of the IMSUM Function
The syntax or the way we write the IMSUM
function is as follows:
=IMSUM(value1,[value2,...])
- = the equal sign is how we begin any function in Google Sheets.
- IMSUM() refers to our
IMSUM
function. This function is used to calculate the sum of a series of complex numbers together. - value1 is the only required argument. This refers to the first complex number or range to add together.
- value2 is an optional argument. This refers to more complex numbers or ranges to add to value1.
Note: We can utilize the IMSUB function
to subtract a series of complex numbers.
The Anatomy of the ARRAYFORMULA Function
The syntax or the way we write the ARRAYFORMULA
function is as follows:
=ARRAYFORMULA(array_formula)
- = the equal sign is how we activate any function in Google Sheets.
- ARRAYFORMULA() refers to our
ARRAYFORMULA
function. This function enables the display of values returned from an array formula into multiple rows and/or columns and the use of non-array functions with arrays. - array_formula is the only required argument. This refers to a range, a mathematical expression using one cell or multiple ranges of the same size, or a function that returns a result greater than one cell.
Common Mistakes in Using IMSUM Function
The IMSUM
function has a straightforward syntax making it simple to use. However, we still need to be careful when using some things to ensure the function properly works.
Firstly, we may have entered the complex number in an incorrect format. We must make sure to use the format a+bi or a-bi, where a and b are real numbers and i is the imaginary unit.
Moreover, remember to input the complex number in quotation marks when entering the number directly into the formula to make it a string.
Secondly, we may have omitted to include the + or – sign between the real and imaginary parts of the complex number. The function will return an error if the complex number has no sign between the parts.
Thirdly, inputting non-complex numbers in the IMSUM
formula. The IMSUM
function only supports complex numbers; thus, using real numbers will not produce good results.
Lastly, check the syntax of the formula. Ensure the syntax of the function call is correct, including the proper placement of commas, the use of parentheses, and the quotation marks for the complex number.
A Real Example of Using IMSUM Function in Google Sheets
Let’s say we have a data set containing complex numbers. We want to return the sum of the series of complex numbers. Our initial data set would look like this:

In this example, we want to calculate the sum of the complex numbers in the data set. We can quickly complete this task using the IMSUM
function.
We can apply the formula below to complete our task:
=IMSUM(A2:A8)

The formula only has one argument, which refers to the first complex number or range containing complex numbers we want to calculate. In this case, we simply selected the range A2:A8, which includes the complex numbers.
In the spreadsheet above, we have multiple complex numbers we want to calculate. We can insert the ARRAYFORMULA function
at the beginning of our formula to easily calculate the sum of multiple complex numbers.
Our formula would become:
=ARRAYFORMULA(IMSUM(A2:A8))

The ARRAYFORMULA
function will apply the IMSUM
function to each cell in the range. Thus, the formula will calculate the sum of the complex numbers and return the result.
Both formulas would yield the same final data set:

You can make your own copy of the spreadsheet above using the link below.
Amazing! Now we can dive into the steps of using the IMSUM
function in Google Sheets.
How to Use IMSUM Function in Google Sheets
1. First, we will select an empty cell to type in our formula. To start, we will type in an equal sign and the function name. Our formula would be “=IMSUM(”.
2. Then, we will simply select the range containing the series of complex numbers. Our final formula would be “=IMSUM(A2:A8)”.
3. We will press the Enter key to return the result.
4. Alternatively, we can apply the ARRAYFORMULA
function to our IMSUM
function. To do this, we will start with an equal sign and the ARRAYFORMULA
function. Our formula would become “=ARRAYFORMULA(”.
5. Then, we will type in the IMSUM
function. In this case, our formula would become “=ARRAYFORMULA(IMSUM(”.
6. Next, we will select the entire range containing the complex numbers. Our final formula would become “=ARRAYFORMULA(IMSUM(A2:A8))”.
7. We will press the Enter key to return the result.
And tada! We have successfully used the IMSUM
function in Google Sheets.
You can apply this guide whenever you need to calculate the sum of a series of complex numbers. You can now use the IMSUM
function and the various other Google Sheets formulas available to create great worksheets that work for you.
That’s pretty much it! Make sure to subscribe to our newsletter to be the first to know about the latest guides and tutorials from us.
