With the radius in A1:

=PI()*A1^2

Or, with the diameter in A1:

=PI()*(A1/2)^2

--
Kind regards,

Niek Otten
Microsoft MVP - Excel

"bhoward425" wrote in message
...
I'm working my way through learning to build spreadsheets. How would I
create
the function to give the area of a circle. I know the formula
A=PI*r(squared)
but don' know the excel functions. I tried "=(PI)*(Power('diameter
cell'/2),2)" but that wouldn't work.