Geometry equations. Animation showing equations for determining the area and volume of a cylinder and its component shapes. The surface area of a cylinder is the area of the top and bottom plus the area of the wall. The area of the top is given by the formula for the area of a circle (pi times the radius of the circle squared). The area of the wall is calculated from multiplying the height (h) of the cylinder with the circumference of the cylinder (2 times pi times the radius of the circle) The volume of a cylinder is the area of the top times the height (h).