The Excel SIN Function

Related Functions:
COS Function
TAN Function
Sine of an Angle

For the simple right-angled triangle below, the sine of the angle θ, is the ratio of the opposite side, o, to the hypotenuse, h.

Right-Angled Triangle

I.e. for the triangle above,

Sine Equation
The trig. ratios are discussed further on the Wikipedia Trigonometric Ratios Page

Function Description

The Excel SIN function calculates the sine of a given angle.

The syntax of the function is:

SIN( number )

Where the number argument is the angle (in radians), that you want to calculate the sine of.

Converting from Degrees to Radians

If your angle is in degrees, you will need to convert it into radians before supplying it to the Sin function.

This can be done by using the Excel Radians function:

=RADIANS( degrees )
An example of this is given below.

Sin Function Examples

The following spreadsheet shows the Excel Sin Function, used to calculate the sine of four different angles.

  A B
1 =SIN( 0.785398163 )  - sin of 0.785398163 Radians
2 =SIN( PI() / 6 )  - sin of π/6 Radians
3 =SIN( -PI() / 3 )  - sin of -π/3 Radians
4 =SIN( RADIANS( -30 ) )  - sin of -30 Degrees
1 0.707106781
2 0.5
3 0.866025404
4 -0.5

Note that in the above examples:

For further information and examples of the Excel Sin function, see the Microsoft Office website.