COS Excel function is an inbuilt trigonometric function in excel which is used to calculate the cosine value of given number or in terms or trigonometry the cosine value of a given angle, here the angle is a number in excel and this function takes only a single argument which is the input number provided.

**Excel COS Function (Table of Contents)**

## COS Excel Function

It is a built-in function in MS Excel. It is categorized under Math Functions in MS Excel. The function returns the cosine of an angle given in radians. The parameter is the value of the angle for which the cosine is to be calculated. The angle can be calculated using the RADIANS function or multiplying it by PI()/180.

### COS Formula

The COS Formula in Excel is as follows:

The COS Formula in excel has one argument which is a required parameter.

*number**= This is a required parameter. It indicates the angle for which the cosine is to be calculated.*

### How to Use COS Function in Excel?

The COS can be used in Excel Worksheet as a Worksheet (WS) function as well as in Excel VBA. As a WS function, it can be entered as a part of the COS formula in a cell of a worksheet. As a VBA function, it can be entered in the VBA code.

Refer to the examples given below to understand better.

### Example #1 – Calculate the value of cos (0)

In this example, cell B2 contains value of the angle for which cosine is to be calculated. Cell C2 has a COS formula associated with it which is RADIANS. COS in excel is assigned to D2 cell. RADIANS(B2) is 0. Further, COS is applied on 0 which is 1.

Hence, the resultant cell D2 has value 1 as COS(0) is 1.

### Example #2 – Calculate the value of cos (30)

** **In this example, cell B3 contains value of the angle for which cosine is to be calculated. Cell C3 has a COS formula associated with it which is RADIANS. COS in excel is assigned to D3 cell. RADIANS(B3) is 0.523598776. Further, COS is applied on 0.523598776 which is 0.866025404.

Hence, the resultant cell D3 has value 1 as COS (0.523598776) is 1.

### Example #3 – Calculate the value of cos (45)

In this example, cell B4 contains value of the angle for which cosine is to be calculated. Cell C4 has a COS formula associated with it which is RADIANS. COS is assigned to D4 cell. RADIANS(B3) is 0.523598776. Further, COS is applied on 0.785398163 which is 0.707106781 .

Hence, the resultant cell D4 has value 1 as COS (0.707106781) is 1.

### Example #4 – Calculate the value of cos (60)

In this example, cell B5 contains value of the angle for which cosine is to be calculated. Cell C5 has a COS formula associated with it which is RADIANS. COS is assigned to D5 cell. RADIANS(B5) is 1.047197551. Further, COS is applied on 1.047197551 which is 0.5.

Hence, the resultant cell D5 has value 0.5 as COS (1.047197551) is 0.5.

### Example# 5 – Calculate the value of cos (90)

In this example, cell B6 contains the value of the angle for which cosine is to be calculated. Cell C6 has a COS formula associated with it which is B6*PI ()/180. COS is assigned to D6 cell. 90*PI ()/180 is 1.570796327**. **The value of PI () is 3.14159. So, it is 90 * (3.14159/180) =1.570796327. Further, COS is applied on 1.570796327 which is 6.12574E-17**. **

Hence, the resultant cell D6 has 6.12574E-17 as COS (1.570796327) is 6.12574E-17.

**Things to remember about the COS** **Function in Excel**

- The COS in excel always expects radians as the parameter for which the cosine is to be calculated.
- If the angle is in degrees, it must be calculated using the RADIANS function or multiply the angle by PI ()/180.

**Usage of COS function in Excel VBA**

The COS in excel can be used in Excel VBA as follows. It serves the same purpose which is to get the cosine value of the angle provided.

Syntax: COS ( Number ) |

#### VBA Example #1

Dim val1 As Double val1 = Cos ( 0 ) val1 :1

Here, val1 is a variable. It is declared as Double which indicates it can hold data with the double data type. The cosine of 0 is 1. Hence val1 holds value 1.

#### VBA Example# 2

Const pi = 3.1415 Dim val As Double'Convert 45 degrees to radians by multiplying by pi/180. val = Cos (45 * pi / 180 ) ' The variable val is now equal to 0.7071067

Here, angle 45 is converted to radians using the same COS formula used in the Excel worksheet.

If a non-numeric value is provided to the Cos in excel then, it will return *Type Mismatch* error in Excel VBA code.

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This has been a guide to COS Function in Excel. Here we discuss the COS Formula in excel and how to use it along with excel example and downloadable excel templates. You may also look at these useful functions in excel –

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