fx
FunctionPedia
Quick Answer

PI Function

Returns the constant π (about 3.14159).

✓ Excel✓ Google SheetsExcel All versions

Syntax

PI
()

Basic Example

Return π

=PI()
Result3.141592654

PI() returns the constant π to about 15 digits of precision.

Advanced Examples

Example 1: Circumference of a circle

Radius 4.

C = 2πr.

=2*PI()*4
Result: 25.13274123
2 × π × 4 ≈ 25.1327, the circumference.

Example 2: Convert π to degrees

Verify radians-to-degrees.

Wrap PI() in DEGREES.

=DEGREES(PI())
Result: 180
π radians equals 180°.

How PI Works

PI() is a constant function that returns the value of π (the ratio of a circle's circumference to its diameter), accurate to the worksheet's 15-digit floating-point precision. It takes no arguments.

1
Select the cell
Click the cell for the result.
2
Enter the formula
Type =PI() with empty parentheses.
3
Press Enter
The value of π appears.

Important Notes & Limitations

  • PI takes no arguments; supplying one (e.g. PI(1)) returns #VALUE!.

  • Precision is limited to the worksheet's ~15 significant digits.

  • It returns a static constant, not a function of any input.

Common Errors & Fixes

#VALUE!Arguments were passed to PI, such as PI(1).

Fix: Call it with empty parentheses: =PI().

Download Practice File

Practice PI with Real Data

Download a sample CSV file with pre-populated data and practice exercises for the PI function. Works in both Excel and Google Sheets.

Works in Google SheetsCompatible with ExcelIncludes exercises

File format: CSV (comma-separated values) - opens in Excel, Google Sheets, and all spreadsheet apps

Frequently Asked Questions

Do I need to pass anything to PI?
No. PI takes no arguments; call it as =PI() with empty parentheses.
How precise is PI()?
It returns about 15 significant digits: 3.14159265358979.
How do I convert PI radians to degrees?
Use =DEGREES(PI()), which returns 180.