Molecular Weight Unit Converter in Excel

From To

0.001

Add-in Formula =PO.UnitConverter(1, "g/mol", "kg/mol")

Excel Lambda

=LAMBDA(x,
  LET(
    ratio, 0.001,
    x * ratio
  )
)(1)

Category Lambda

=LAMBDA(x, from, to,
  LET(
    f, SWITCH(from,
      "kg/mol", 1,
      "g/mol", 0.001,
      "lbm/lbmol", 0.001),
    t, SWITCH(to,
      "kg/mol", 1,
      "g/mol", 0.001,
      "lbm/lbmol", 0.001),
    x * f / t
  )
)(1, "g/mol", "kg/mol")

How to save as a reusable Excel function

LAMBDA is a built-in Excel feature (Microsoft 365) that lets you create custom functions without VBA. The formulas above work as-is when pasted into a cell.

To save a LAMBDA as a reusable named function:

Go to Formulas → Name Manager → New
Enter a name, e.g. ConvertMolecularWeight
In Refers to, paste the LAMBDA formula without the trailing invocation (...)
Click OK

Now use =ConvertMolecularWeight(1, "g/mol", "kg/mol") anywhere in your workbook — no add-in required.

Conversion Factors (base: kg/mol)

Unit	Name	Factor
kg/mol	kilogram per mole	1
g/mol	gram per mole	0.001
lbm/lbmol	pound-mass per pound-mole	0.001