I have a 52" diameter cylinder that 13' 6" (162") tall. I need to determine the Cubic Yards that fit in there.
Be sure you are using inside measurements. The volume of a cylinder is V = (pi/4)*d²*h, but consistent units have to be used. Starting with your numbers in inches
V = 0.785 * 52² * 162 = 344042 in³
There are 1728 in³ in a cubic foot, so 199.1 ft³
and there are 27 ft³ in a cubic yard so 7.37 yd³
You could equally well convert inches to yards (36" = 1 yd) and get to the same number with 1.444 yd diameter, and 4.5 yd height, and get 7.37 yd³ direct;y.