You need to multiply the volume of a cone by 3 to get the volume of its corresponding cylinder (a cylinder with the same base radius and perpendicular height).
As in:
Vol. of a cylinder= πr²h
and Vol. of a cone= ⅓πr²h
So assuming volume of a cone is ⅓V, then the volume of the cylinder will be ⅓V × 3 which equals V.