How calculate Fluid volume in horizontal cylinder?

The volume of a cylinder in any position will be the area of the circular end, or top, times the length, or height, along a side. The area of a circle is pi x radius2, where the radius ("r") is half the diameter ("d"), the distance across the circle. Calling the length or height of the cylinder "h", the volume of the cylinder is calculated as: V = (pi x r2)h = (3.1416 x (d/2)2)h Example: What is the volume of cylinder 12" long and 6" across the circular end? V = (pi x r2)h = (pi x (d/2)2)h = (3.1416 x (6/2)2)12 = (3.1416 x 32)12 = (3.1416 x 9)12 = 28.2744 x 12 = 339.3 cubic inches. Be sure to use the same units for r, d, and h. Pi is always 3.1416 (rounded).