A function is a built-in formula that helps perform calculations in Excel. It uses specific values in a set order. Excel has many common functions. These include finding the sum, average, count, maximum, and minimum of a range of cells.

To use functions correctly, you need to understand their parts. You also need to know how to create arguments. Arguments help calculate values using cell references.

Here’s a simplified and easy-to-read version of the description:

Understanding Functions in Excel

A function in Excel follows a specific structure called syntax. The basic syntax includes:

  1. An equals sign (=) to start the function.

  2. A function name like SUM or AVERAGE.

  3. One or more arguments inside parentheses. Arguments contain the data to be calculated.

For example, the function below adds values from cells A1 to A20:
=SUM(A1:A20)

Working with Arguments

Arguments can be:


  • A single cell (e.g., A1)

  • A cell range (e.g., A1:A10)

  • Multiple arguments separated by commas (e.g., =SUM(A1:A3, C1:C2, E1))


Example:
=AVERAGE(B1:B9) → Finds the average of numbers in B1 to B9.

=SUM(A1:A3, C1:C2, E1) → Adds values from different ranges and a single cell.

Common Excel Functions

Here are some useful functions in Excel:

  • SUM: Adds numbers in the argument.

  • AVERAGE: Finds the average of values.

  • COUNT: Counts how many numbers are in a range.

  • MAX: Finds the highest value in a range.

  • MIN: Finds the lowest value in a range.

Creating a Function

Using AutoSum

AutoSum helps insert common functions quickly.


  1. Select a cell where you want the result.

  2. Click the AutoSum button (found in the Home tab).


  3. Choose a function (e.g., SUM).

  4. Excel will guess the cell range. If incorrect, change it manually.


  5. Press Enter to calculate the function.


Shortcut: Press Alt + = to insert SUM automatically.

Entering a Function Manually

  1. Select the cell where you want the function.


  2. Type = followed by the function name.


  3. Enter the argument inside parentheses.


  4. Press Enter to get the result.


Example:
=AVERAGE(C3:C9) → Adds numbers in C3 to C9, then divides by the count of numbers.


Using the Function Library

Excel has many functions. You can find them in the Function Library (under the Formulas tab). Functions are grouped into categories like Financial, Logical, and Date & Time.

To insert a function from the library:

  1. Click the Formulas tab.


  2. Select a function category.

  3. Click a function from the list.

  4. Enter the required arguments and press OK.


If you're having trouble finding the right function, the Insert Function command allows you to search for functions using keywords.


The AutoSum command allows you to automatically return results for common functions, like SUM, AVERAGE, and COUNT.


The Recently Used command gives you access to functions you've recently worked with.


The Financial category contains functions for financial calculations like determining a payment (PMT) or interest rate for a loan (RATE).


Functions in the Logical category check arguments for a value or condition. For example, if an order is more than $50, add $4.99 for shipping; if it is more than $100, do not charge for shipping (IF).


The Text category contains functions that work with the text in arguments to perform tasks, such as converting text to lowercase (LOWER) or replacing text (REPLACE).


The Date & Time category contains functions for working with dates and time and will return results like the current date and time (NOW) or the seconds (SECOND).


The Lookup & Reference category contains functions that will return results for finding and referencing information. For example, you can add a hyperlink to a cell (HYPERLINK) or return the value of a particular row and column intersection (INDEX).


The Math & Trig category includes functions for numerical arguments. For example, you can round values (ROUND), find the value of Pi (PI), multiply (PRODUCT), and subtotal (SUBTOTAL).


More Functions contains additional functions under categories for Statistical, Engineering, Cube, Information, and Compatibility.



Using the Insert Function Command

If you don’t know the exact function name, Insert Function helps you find one.

  1. Select a cell.


  2. Click Insert Function (on the Formulas tab).


  3. Type keywords describing the calculation (e.g., "count days").


  4. Select a function from the list and click OK.

  5. Enter the required arguments and press OK.


Example: NETWORKDAYS calculates business days between two dates.

Copying Functions

After inserting a function, you can apply it to other cells using the fill handle:

  1. Select the cell with the function.

  2. Drag the fill handle (small square at the cell's bottom-right corner).


  3. The function copies to other cells automatically.