Pi is a constant value in arithmetic which is used for calculations, where in arithmetic we have the value up to two decimals but in excel we have an inbuilt PI() function which stores the exact value up to 15 decimals, this function is used in different other formulas to for further calculation.
PI in Excel – Table of Contents
PI Formula in Excel
PI is a mathematical constant value that shows the ratio between a circle’s circumference and its diameter. In excel we have a built-in function called PI to calculate the values. Before I talk about PI formula in excel, let me introduce you to what is meant by pi in mathematics first. The word PI’s most popular symbol is π and its constant value is 3.14159265358979, which can also return as 22/7.
Pi is a ratio of a circle’s circumference to its diameter. In simple words, Pi is the value of the overall circle around is divided by all the way across of the circle. For a better understanding look at the below image.
The entire circle is called Circumference, so the PI formula will be as follows.
π = Circumference / Diameter
Now I will show you the simple example of how to calculate PI in your own home. Take any circular shape vessel in your home.
Now measure the circle of the above bowl. I have measured and I got the value as 82 CM. This is called as Circumference.
Now measure across of the bowl as shown in the below image. I have measured and I got the value as 26 CM. This is called Diameter.
Now in order to get the PI value use the formula Circumference / Diameter.
i.e. 82 Cm / 15 Cm = 3.1538.
In this way, the PI value can be calculated in real life. Now in the next section of the article, we will see how to calculate PI in excel.
Formula of PI Function in Excel
The syntax of PI does not have any arguments rather it simply returns the values of 3.141592653589790.
In excel PI is categorized as Math & Trigonometry excel function. The moment you apply the PI function it will return the value approximate to 15 digits i.e. 3.141592653589790
How to Insert PI Formula in Excel?
Since PI does not have any arguments let me show you how to insert PI formula in excel. In any of the cell, your excel worksheet opens the function PI and simply close the brackets, we would have PI value here.
PI value is an irrational number, so no limit for decimal points. Excel can show up to 30 decimal points but any digit after 14 decimal points will be shown as zero.
How to Use PI Formula in Excel?
Below is the example of the PI formula in excel.
Now take an example of finding the cake’s cost per Inch. When I enquired about the cake for a New Year party, I got two quotes from the store.
Two kg’s of Cake which is 10 CM will cost me 500 rupees.
Five kg’s Cake which is 15 CM will cost me 600 rupees.
Now I want to find out the cost per inch of the cake and order the cheapest cake for the party.
Cake size is nothing but the diameter of the circle. The radius of the circle is always the exact half of the diameter. So arrive Radius of the cake by dividing the diameter by 2.
So we got the radius as 5 for 10 inche cake.
Drag the formula to cell C3.
Now we need to calculate the area of the circle (AOC). A formula to calculate the AOC is as follows.
AOC = PI * R2
R = Radius of the circle.
Let’s apply the formula to find the AOC. AOC is PI times radius squared.
AOC of both the cakes is given below.
Now calculate the cost per inch. A formula is Cost / AOC.
Cost per inch for both the cakes are as follows.
From the above calculation, it is better to buy a cake which is 15 inches costs 4.53 rupees per inch.
Like this, we can use the PI to calculate the cost and take a decision.
Things to Remember
- In order to insert PI symbol π in excel, you need to hold the ALT key and type 227 from the number keypad.
- The PI function can also be used in VBA under Application.Worksheet functions.
- Radius is always half of the diameter.
This has been a guide to PI in Excel. Here we discuss how to use PI Formula in excel along with practical examples and downloadable excel template. You may learn more about excel from the following articles –