Even if you don’t know what Pi is, I am sure you have seen the symbol π.

In this tutorial, I will cover what Pi means and how to use Pi in Excel.

## What is Pi (π) and What Does it Mean?

The symbol, *pi* or is a mathematical constant that is approximately equal to **3.142**. It represents the ratio of a circle’s circumference to its diameter. In radians, it provides the value of a half-turn.

As such, it is often used in formulas relating to circles.

In business applications, the value of *pi* is used in doing geometric calculations, such as to find the area of office space, the circumference of a product, etc.

Although we usually round off the value of *pi* to just 2 decimal places (for ease of calculation), the actual value can go up to trillions of decimal places.

Excel stores the value of *pi* accurately up to 14 decimal places, and this value can be accessed using the PI function.

## How to Use Pi in Excel

In Excel, the PI function is used to represent the value of *pi*. This function is classified as a Math or Trigonometric function.

The syntax for the PI function is very simple:

=PI()

The function does not take any arguments and returns the value of constant *pi* accurate up to 15 digits or 14 decimal places.

So, if you want to use the value of *pi* in a function or formula, you simply need to use the function PI in its place.

Let us see a few small examples to understand how the PI function works:

In the above figure,

- The first formula only gives the value of , i.e. 3.14159265358979. If you want to round it off to lesser decimal places, you can format the cell by right-clicking on it, navigating to
*Format Cells-> Number->Number,*and then enter the number of decimal places you want. For example, here is the value of pi up to 3 decimal places. - The second formula returns the value of
*pi*in degrees. The DEGREES function is used to convert a value in radians to its equivalent value in degrees. Notice the value of in degrees is 180°, which is half a circular turn. That means 2 times its value is a full circular turn. - The third formula calculates the circumference of a circle, of radius 5. The formula for the circumference of a circle is 2r, where r is the radius of the circle. So to find the circumference of a circle of radius 5, you use the formula =2*PI()*5. In the same way, you can find the circumference of a circle of any given radius.
- The fourth formula calculates the area of a circle, of radius 5. The formula for the area of a circle is r2, where r is the radius of the circle. So to find the area of a circle o radius 5, you use the formula =PI()*5^2. Here, the
*caret*symbol (‘^’) represents raising the power of a value. In the same way, you can find the area of a circle of any given radius. - The fifth formula calculates the area of a circle, with its radius given in cell A4.

In this tutorial, we showed you **how to use the PI function in Excel** to either get the value of PI (in radians or degrees) or to perform calculations that involve this constant.

We hope our simple examples and explanations have made it easy for you to understand and apply the concept to your data.

**Other Excel tutorials you may find useful:**

- How to Use e in Excel | Euler’s Number in Excel
- How to Calculate Antilog in Excel
- How to Calculate Standard Error In Excel
- How to Square a Number in Excel