The PI function returns 3.14159265358979 -- the value of constant pi returned by the function is accurate to 15 digits -- in Microsoft Excel 2013 and Office 365. Use it in your formulas as PI(); the function does not accept any arguments. For example, you can use it to calculate the volume of a sphere. To get the most accurate result, format the cell that contains the formula and change the number of decimal places to 14.
Open the spreadsheet you want to edit in Excel 2013 or create a new spreadsheet. Type the radius of the sphere into one of the cells, or locate the cell that contains it.
Right-click the cell where you want to display the volume of the sphere and choose Format Cells from the context menu. The Format Cells dialog displays with the Number tab selected by default.
Select Number from the Category section to change the format of the cell and then type 14 into the Decimal Places field to use all 14 digits of constant pi in the formula. Click OK.
You can select to use fewer digits, but Excel automatically approximates the value of pi -- for example, it returns 3.142 if you use three decimal places.
Format the cells further by changing the options on the Alignment, Font, Border and Fill tabs.
Type =4/3_PI()_Cell^3 into the Formula field and replace "Cell" with the cell that contains the radius of the sphere. Press Enter to calculate the volume of the sphere and display it in the selected cell.
The PI() function returns the value of pi. "/" is the division operator, "*" is the multiplication operator and "^" is the power operator.
To display the value of pi in a cell, type "=PI()" into the Formula field and press "Enter".
To view the formula, instead of the result, in the selected cell, press "Ctrl-`".
If you use fewer than 14 decimals, Excel approximates the value of pi, changing the results of your formulas.