Surface Area Calculator
Calculate the surface area of a sphere, cube, cylinder, or cone from its dimensions.
Total surface area
314.1593
The full outer area of the solid, in square units.
4πr²
314.1593
How it works
Surface area is the total area of a solid's outer skin — think of the amount of wrapping paper it would take to cover it. Pick the shape you're working with, then enter the dimensions the calculator asks for: a radius, an edge, a height, or some combination.
Each solid has its own formula. A sphere is 4πr². A cube is 6 times the area of one face, or 6a². A cylinder adds its curved side (2πrh) to its two circular ends (2πr²). A cone combines its base (πr²) with its slanted side (πr·l), where the slant height l comes from √(r² + h²).
For the cylinder and cone the tool breaks the answer into its lateral and base pieces, and for the cone it also reports the slant height it computed along the way. That makes it easier to see where the total comes from and to catch a mistyped dimension.
Frequently asked questions
Which dimensions do I need for each solid?
A sphere needs its radius; a cube needs one edge length; a cylinder needs a radius and a height; and a cone needs a radius and a height (the slant height is derived for you). The form only shows the fields the chosen solid requires.
What's the difference between lateral and total surface area?
Lateral surface area is just the curved or slanted side of a solid, leaving out the flat ends. Total surface area adds the bases back in. This tool reports the total and, for cylinders and cones, shows the lateral and base parts separately.
How is a cone's slant height found?
The slant height runs from the tip of the cone down to the edge of its circular base. Because the radius and height meet at a right angle, it's the hypotenuse: l = √(r² + h²). The lateral area then equals πr·l.