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.

Calculating the area of a circle in Excel

To calculate the area of a circle in Excel, use the following formula:

Here's a breakdown of what each part of the formula means:

1. PI(): This is an Excel function that returns the value of pi (approximately 3.14159).
2. radius: This is the radius of the circle, which you can input directly into the formula or reference a cell that contains the radius value.
3. ^2: This is the exponent operator in Excel, which raises the radius value to the power of 2 (i.e. squared).

To use this formula in your spreadsheet, simply replace "radius" with the appropriate cell reference or value. For example, if your radius value is in cell A1, the formula would look like this:

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.

On 1/27/2010 10:19 AM, bhoward425 wrote:
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.

see Excel help for PI.
If radius is in cell A1, either of these formulas should work:
=PI()*A1^2
=PI()*A1*A1

Bill

I can get the areas of individual diameters, but I need to get the total for a range of diameters. If I have 10 different measurements of tree limbs, I need the total area of the 10 limbs. Right now, I have to calculate each one separately and then add them up.

=(3.14*(C2/2)^2)+(3.14*(D2/2)^2)+(3.14*(E2/2)^2)+(3.14*(F2/2)^2)+(3.14*(G2/2)^2)+(3.14*(H2/2)^2)+(3.14*(I2/2)^2)+(3.14*(J2/2)^2)+(3.14*(K2/2)^2)+(3.14*(L2/2)^2)+(3.14*(M2/2)^2)

There otta be a better way ... and I broke me head trying to find it. Not a math whiz, but competent with simple formulas. This is a practical exercise for a horticulturalist who consults on trees all the time.