Mass Unit Converter in Excel

From To

0.001

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

Excel Lambda

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

Category Lambda

=LAMBDA(x, from, to,
  LET(
    f, SWITCH(from,
      "kg", 1,
      "g", 0.001,
      "mg", 1E-06,
      "t", 1000,
      "st", 6.35029318,
      "lbm", 0.45359237,
      "ozm", 0.028349523125,
      "ozm[troy]", 0.0311034768,
      "ton[UK]", 1016.0469088,
      "ton[US]", 907.18474),
    t, SWITCH(to,
      "kg", 1,
      "g", 0.001,
      "mg", 1E-06,
      "t", 1000,
      "st", 6.35029318,
      "lbm", 0.45359237,
      "ozm", 0.028349523125,
      "ozm[troy]", 0.0311034768,
      "ton[UK]", 1016.0469088,
      "ton[US]", 907.18474),
    x * f / t
  )
)(1, "g", "kg")

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. ConvertMass
In Refers to, paste the LAMBDA formula without the trailing invocation (...)
Click OK

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

Conversion Factors (base: kg)

Unit	Name	Factor
kg	kilogram	1
g	gram	0.001
mg	milligram	1E-06
t	tonne	1000
st	stone	6.35029318
lbm	pound-mass	0.45359237
ozm	ounce-mass	0.028349523125
ozm[troy]	troy ounce-mass	0.0311034768
ton[UK]	UK ton-mass	1016.0469088
ton[US]	US ton-mass	907.18474