Write a formula once, name it, and call it everywhere like a built-in function. A named LAMBDA turns your own logic — a tax calc, a custom format — into =MyFunction(…).
=GrossUp(A1, 0.08) works anywhere in the workbook, just like a native function.
The example
A reusable “gross-up” function.
| A | B | |
|---|---|---|
| 1 | Call | Result |
| 2 | =GrossUp(100, 0.08) | 108 |
The formula
Define once in Name Manager, call anywhere:
How it works
Name Manager turns a LAMBDA into a function:
- Build and test the LAMBDA in a cell first:
=LAMBDA(net, rate, net*(1+rate))(100, 0.08). - Open Formulas → Name Manager → New. Enter a Name and paste the LAMBDA (without test arguments) in Refers to.
- Click OK. The name is now a custom function usable across the workbook.
- Call it like any function:
=GrossUp(A1, 0.08). Update the definition once and every call updates.
Share with a workbook. Named LAMBDAs live in the workbook, so they travel with the file. For a library across files, save them in a template, or use Excel’s Advanced Formula Environment / LAMBDA library add-in to manage and import them.
Try it: interactive demo
GrossUp(net, rate).
Variations
Test inline first
Call a LAMBDA immediately:
No-argument constant
A named value too:
Compose functions
Use one named LAMBDA inside another.
Pitfalls & errors
Drop the test arguments. In Name Manager, the Refers-to is just =LAMBDA(…) — don’t include the (100, 0.08) call, or it stores a value, not a function.
Name rules apply. No spaces, can’t look like a cell reference, must start with a letter.
365/2021 only. Named LAMBDAs need LAMBDA support; older Excel can’t open them as functions.
Practice workbook
Frequently asked questions
How do I create a custom function in Excel without VBA?
Do named LAMBDAs work in other workbooks?
Why did my named LAMBDA store a number instead of a function?
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