The surface area $SA$ of a three-dimensional shape is the total area of all the surfaces of the shape. The lateral area $LA$ is the total area of all lateral surfaces, the surfaces of the shape that are not bases. Lateral area can be defined for polyhedrons, cones, and cylinders. In these instances, the surface area of the shape can be calculated by the formula below.

The net of a solid can be helpful to visualize the surfaces of a three-dimensional figure.

Some three-dimensional shapes, like spheres, have no bases. In these cases, a formula specific to that solid can often be applied, such as the one used to calculate the surface area of a sphere.