Area Unit Converter in Excel

From To

40.4687261

Add-in Formula =PO.UnitConverter(1, "acre", "are")

Excel Lambda

=LAMBDA(x,
  LET(
    ratio, 40.4687260987425,
    x * ratio
  )
)(1)

Category Lambda

=LAMBDA(x, from, to,
  LET(
    f, SWITCH(from,
      "m2", 1,
      "km2", 1000000,
      "dm2", 0.01,
      "cm2", 0.0001,
      "mm2", 1E-06,
      "mi2", 2589998.47031952,
      "yd2", 0.83612736,
      "ft2", 0.09290304,
      "in2", 0.00064516,
      "ha", 10000,
      "acre", 4046.87260987425,
      "are", 100),
    t, SWITCH(to,
      "m2", 1,
      "km2", 1000000,
      "dm2", 0.01,
      "cm2", 0.0001,
      "mm2", 1E-06,
      "mi2", 2589998.47031952,
      "yd2", 0.83612736,
      "ft2", 0.09290304,
      "in2", 0.00064516,
      "ha", 10000,
      "acre", 4046.87260987425,
      "are", 100),
    x * f / t
  )
)(1, "acre", "are")

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

Now use =ConvertArea(1, "acre", "are") anywhere in your workbook — no add-in required.

Conversion Factors (base: m2)

Unit	Name	Factor
m2	square metre	1
km2	square kilometre	1000000
dm2	square decimeter	0.01
cm2	square centimetre	0.0001
mm2	square millimetre	1E-06
mi2	square mile	2589998.47031952
yd2	square yard	0.83612736
ft2	square foot	0.09290304
in2	square inch	0.00064516
ha	hectare	10000
acre	acre	4046.87260987425
are	are	100