help with volume measurement
 

I usually do pretty good figuring volumes of containers, but most of the time the containers are pretty big. This one I'm having a little difficulty with.

I have a cylinder that is 5" in diameter and 20" in length. I need to know how many gallons it will hold.

I did the 3.14 X the radius squared X height = volume formula, but keep coming up with 21 gallons! :o Maybe somehow I'm messing up the decimal point and it should be 2.1 gallons, but for the life of me I can't get it right. I think my errors are because I'm dealing with fractions of a foot instead of whole feet.

Thanks for the help!

chaikwa.

pi*2.5^2*20=393 in^3
Convert.exe says 393in^3 = 1.70 Gallons

1in^3 = .00433 Gallons

Thank you very much!

chaikwa.