SUM Function in Excel

The syntax of the function is shown in the following image:

The function accepts the following arguments:

• Number1: This is the first numeric value to be added.
• Number2: This is the second numeric value to be added.

The “number1” argument is required while the subsequent numbers (“number 2”, “number 3”, etc.) are optional.

To enter the SUM function manually, type “=SUM” followed by the arguments.

The alternative steps to enter the SUM excel function are listed as follows:

1. In the Formulas tab, click the “math & trig” option, as shown in the following image.

2. From the drop-down menu that opens, select the SUM option.

3. In the “function arguments” dialog box, enter the arguments of the SUM function. Click “Ok” to obtain the output.

The AutoSum option is the fastest way to add numbers in a range of cells. It automatically enters the SUM formula in the selected cell.

Let us work on an example to understand the working of the AutoSum option. We want to sum the list of values in A2:A7, shown in the succeeding image.

Let us consider a few examples to understand the usage of the SUM function. The examples #1 to #5 show an image containing a list of numeric values.

Example #1

We want to sum the cells A2 and A3 shown in the succeeding image.

Apply the formula “=SUM(A2, A3).” It returns 20.7 in cell C2.

Example #2

We want to sum the cells A3, A5, and the number 45 shown in the succeeding image.

Apply the formula “=SUM (A3, A5, 45).” It returns 58.8 in cell C2.

Example #3

We want to sum the cells A2, A3, A4, A5, and A6 shown in the succeeding image.

Apply the formula “=SUM (A2:A6).” It returns 135.4 in cell C2.

Example #4

We want to sum the cells A2, A3, A5, and A6 shown in the succeeding image.

Apply the formula “=SUM (A2:A3, A5:A6).” It returns 35.4 in cell C2.

Example #5

We want to sum the cells A2, A3, A5, A6, and the number 500 shown in the succeeding image.

Apply the formula “=SUM (A2:A3, A5:A6, 500).” It returns 535.4 in cell C2.

The rules governing the usage of the function are listed as follows:

• The arguments supplied can be numbers, arrays, cell references, constants, ranges, and the results of other functions or formulas.
• While providing a range of cells, only the first range (cell1:cell2) is required.
• The output is numeric and represents the sum of values supplied.
• The arguments supplied can go up to a total of 255.

Note: The SUM excel function returns the “#VALUE!” error if the criterion supplied is a text string longer than 255 characters.

The drawbacks of the function are listed as follows:

• The cell range supplied must match the dimensions of the source.
• The cell containing the output must always be formatted as a number.

The built-in formulas of Excel can be expanded by nesting one or more functions inside another function. This permits multiple calculations to take place in a single cell of the worksheet.

The nested function acts as an argument of the main or the outermost function. Excel calculates the innermost function first and then moves outwards.

For example, the following formula shows the SUM function nested within the ROUND function:

For the given formula, the output is calculated as follows:

• First, the sum of the values in cells A1 to A6 is computed.
• Next, the resulting number is rounded to three decimal places.

With Microsoft Excel 2007, nested functions up to 64 levels are permitted. Prior to this version, one could nest functions only till 7 levels.