The volume of a cylinder is calculated by multiplying its base area with its height: $$V=Bh.$$ The base area is the area of either circle or ellipse. If the shape is a circle, the base area can be calculated with $\pi r^2,$ and the volume is then given by $$V=\pi r^{2}h.$$

and the height is measured perpendicular to the base. By Cavalieri's principle, this formula still holds true for skewed cylinders.