LAMBDA lets you turn a formula into a named reusable function inside Excel. It is like creating your own worksheet function without using VBA or macros.
Does this affect you?
Use this for Excel for Microsoft 365 on Windows, Mac, or the web with current updates. LAMBDA is not available in Excel 2021, Excel 2019, or older perpetual-license versions.
Build a basic LAMBDA formula
Test the syntax directly in a cell first.
- Click an empty cell.
- Type =LAMBDA(.
- Enter parameter names separated by commas, such as celsius.
- Add the formula using those names, such as =LAMBDA(celsius,celsius*9/5+32).
- To test immediately, add a value call at the end: =LAMBDA(celsius,celsius*9/5+32)(100).
- Press Enter. The example returns 212.
The final (100) is only for testing. Remove it when saving the LAMBDA as a named function.
Save it as a reusable named function
Name Manager makes the function callable anywhere in the workbook.
- Open Formulas > Name Manager.
- Click New.
- Enter a name such as CtoF. Names cannot contain spaces or start with a number.
- In Refers to, paste the LAMBDA formula without the test call: =LAMBDA(celsius,celsius*9/5+32).
- Click OK, then Close.
- Use it in a cell with =CtoF(A2).
More control
Use LET inside complicated LAMBDAs
LET lets you define intermediate names inside a formula. It keeps a long LAMBDA readable instead of burying every calculation in one nested expression.
Recursion is possible but advanced
A LAMBDA can call its own saved name from inside its formula. That enables recursive calculations, but most everyday workbook problems do not need it.
Fix #CALC during testing
#CALC often means the number of test values after the LAMBDA does not match the number of parameters. A two-parameter LAMBDA needs exactly two supplied values.
Named functions stay in one workbook
A LAMBDA saved in Name Manager belongs to that workbook. To share it, copy a sheet that uses it into another workbook or recreate the same named formula there.
Sources
- Microsoft Support – LAMBDA function (2025)
- Microsoft Support – Create custom reusable functions with the LAMBDA function (2025)
- Microsoft Support – Use the Name Manager (2025)