How to Insert Pi in Excel (2 Easy Ways)

When working with mathematical data or equations, you may often need to insert special characters, such as the pi symbol (π), also referred to as the pi sign, to represent the mathematical constant π. Excel has several ways in which you can insert pi in Excel, and also how to use pi (the number) in calculations, we'll look at both in this post but first:

What is Pi?

Pi is a mathematical constant representing the ratio of a circle's circumference to its diameter. It is written as the Greek letter π. It is an irrational number, which means it cannot be expressed as a simple fraction and its decimal representation goes on infinitely without repeating. The approximate value of pi is 3.14159, but it's commonly rounded to 3.14 or expressed as 22/7 in fractional form. Pi is used extensively in mathematics, science, and engineering for calculations involving circles, spheres, and trigonometry. It is one of the most critical and well-known mathematical constants.

While there are a few different ways to use pi (this isn't a math post 😊), we'll just look at one and use this example throughout the post. Let's say we have a round garden and we wanted to find the area of the circle which is 10 meters (m) in diameter, the circumference would be:

Circumference = Pi x diameter
= 3.14 x 10 m
= 31.4 m

How to Insert Pi in Excel

One of the most common requirements when working with mathematical formulas in Excel is inserting the pi symbol. Here are a couple of different methods you can use to accomplish this:

1. Shortcut Keys Method

The first method is the shortcut keys method (or keyboard shortcut method) provides a quick and easy way to insert the pi symbol into your Excel cells. Follow these steps:

Step 1: Position your cursor in the Microsoft Excel spreadsheet cell where you want to insert the pi symbol.

Step 2: Press and hold the “Alt” key on your keyboard.

Step 3: While holding the “Alt” key, type “227” on the numeric keypad of your computer keyboard. Ensure Num Lock is enabled.

Step 4: Release the “Alt” key, and the pi symbol (π) will appear in the selected cell.

2. Insert Ribbon Method

Another straightforward way to insert the symbol of pi in Excel is by using the Symbol button on the Insert Ribbon. Here's how you can do it:

Step 1: Position your cursor in the Microsoft Excel spreadsheet cell where you want to insert the pi symbol.

Step 2: Click on the Insert Tab of the Excel ribbon

Step 3: Click on the Symbol button; this will open the Symbol Dialogue Box. This opens a list of symbols like the pi symbol.

Step 4:Leave the Font as “normal test” and ensure the Subset is “Greek and Coptic”. You must scroll down a little before the pi symbol (π) is shown in the table. Another option is to update the character code to “03C0” ensuring that the from is “Unicode (hex)”. This will take you directly to the pi symbol in the table.

Once you've used this method a time or two, the pi symbol will start showing the Recently Used Symbols so you won't need to search each time.

How to Use Pi In Excel

The PI Function

If you frequently work with mathematical calculations involving pi in Excel, you can utilize the built-in PI function (sometimes called the pi formula) to return the value of pi or use the value in calculations. The PI Function returns the value of pi – 3.14 and depending on how your cell is formatted will depend on how many decimals are shown. More on that later. Here's how to use this Excel formula:

Step 1: Select the cell where you want to display the pi value.

Step 2: Type “=PI()” (without quotation marks) in the formula bar.

Step 3: Press Enter, and the cell will display the value of pi.

Using the garden example above where the diameter is 10 meters, if we wanted to use the PI Function to determine the circumference of the garden, our formula would look like this:

= PI x diameter
=PI()*10
= 3.14 m

Change the number of decimal places for the pi value in Excel

While the pi value goes on for infinity, Excel will give you up to 14 decimal places (3.14159265358979), all decimals after that will be a value of 0. Note; the example above only has 6 decimals and that is due to the width of my cell. If I made my cell wider, more decimals will show, up to 9 decimals unless I format the cell to show more decimals.

So can you decide how many decimal places you want? Absolutely. Simply format the cell containing the pi value by selecting the “Decrease Decimal” button on the Home tab of the Excel ribbon. Each time you click the button, the number is reduced by one decimal.

Conversely, if you select the “Increase Decimal” button, more decimals will appear. Anything past 14 decimals will just be zeros.

That's it! Easy as…pi!

See what I did there? I know, I know! I'm a nerd and I love it! 😉

By using the shortcut keys or the Insert tab of the Excel ribbon, you can easily insert the pi symbol into your cells. As a bonus, you've also learned how to use the PI formula to calculate the circumference of a circle. With these techniques at your disposal, you can enhance the accuracy and clarity of your mathematical work in Excel.