Excel is a spreadsheet program that is developed for **Windows**, **Mac**, **Android**, and **iOS**. It helps to perform calculations on your PC. It offers built-in formulas and functions for performing mathematical operations. You can also use **graphic tools**, **pivot tables**, and a macro programming language called **Visual Basic for Applications **(VBA).

In this article, you will learn the **usage of Excel ACOS Function** with its syntax, explanation, and examples. Get an official version of** MS Excel** from the following link:

https://www.microsoft.com/en-in/microsoft-365/excel

## Explanation of **ACOS Function**

- It is one of the
**built-in functions**in Microsoft Excel. - This function
**returns the inverse cosine of a given number in radians**. - The inputs to the ACOS function must be in between
**-1**and**1**. - For example,
**ACOS(-0.25)**will return the output value as**1.823**

**Syntax**

- Here, you will see the syntax of the ACOS function.
- To apply this function on your spreadsheet, you have to
**select a cell**and**enter the formula**in the following format. - Once you enter the formula, just
**click**on the**Enter**button to get the result.

**=ACOS(number)**

**Parameter Description**

**Number** – The input value to get the inverse cosine number. It should be in between -1 and 1.

**Note:**

1) If the argument is a non-numeric value such as letters or special characters and then it will return **#VALUE! Error**.

2) If the input number is greater than 1 or less than -1, it will return the **#NUM! Error**.

**Examples**

Here, we come up with some examples to know how to use the ACOS function in the Excel spreadsheet.

- Initially, you have to open your Excel workbook on your PC and launch a worksheet that has data.
- For instance, we have given the
**input**values in**Column B**and we will get the corresponding inverse cosine values in Column D.

- Then, you have to
**enter the formula**in the cell as shown below to get the result.

- After entering the formula, you need to
**click**the**Enter button**to get the output, as shown below. You can drag down the cell to fill the remaining cells.

## Input that Causes Error

- If the argument is a non-numeric value and then it will return
**#VALUE!**Error. - In case, the input number is greater than 1 or less than -1, it will return the
**#NUM!**Error.

**Closure**

In this article, you can grasp the usage of the **Excel ACOS Function** with its syntax, explanation, and examples. Drop your **feedback** in the comment section. To learn more about Excel functions, then visit our webpage Aawexcel.com.

## Video Tutorial

The following video will show you how to apply the ACOS function in your worksheet with a few examples.

**Read Also**

- How to Use Excel FLOOR.MATH Function?
- How to Use Excel FLOOR Function?
- How to Use Excel CEILING.PRECISE Function?
- How to Use Excel CEILING Function?
- How to Use Excel GCD Function?

Hi there, I’m **Sridhar** – an Excel enthusiast with over **10 years** of experience working with software. I’m passionate about using Excel to solve complex problems and streamline business processes. Over the years, I have helped businesses of all sizes to improve their **operations and save time and money**.

Aside from working with Excel, I also enjoy writing and sharing my knowledge with others. You’ll often find me contributing to the AAW Excel blog, where I provide tips, tricks, and tutorials that are easy to understand for readers of all skill levels.