Surface Area Calculator 2026
Instantly calculate the total and lateral surface area of any 3D shape. Supports cubes, cuboids, spheres, cylinders, cones & pyramids with step-by-step formulas.
Shape & Dimensions
Select a 3D shape and enter its measurements
All sides of a cube are equal
Distance from centre to the surface
The diagonal height from base edge to apex
Height of a triangular face from base to apex
Surface Area Results
Total & lateral area with formulas
Select a shape, enter dimensions, then click Calculate Surface Area to see your results with step-by-step working.
Surface Area Formulas
Quick reference for the total surface area formulas of common 3D shapes. All formulas use standard geometric notation.
| Shape | Total Surface Area Formula | Key Variables |
|---|---|---|
| 🟦 Cube | SA = 6a² | a = side length |
| 📦 Cuboid | SA = 2(lw + lh + wh) | l = length, w = width, h = height |
| 🔵 Sphere | SA = 4πr² | r = radius |
| 🥫 Cylinder | SA = 2πr² + 2πrh | r = radius, h = height |
| 🔺 Cone | SA = πr² + πrl | r = radius, l = slant height |
| 🔻 Square Pyramid | SA = b² + 2b·s | b = base side, s = slant height |
Surface Area FAQ
Learn more about surface area calculations, formulas, and real-world applications for geometry and construction projects.
Surface area is the total area of all the outer faces or surfaces of a three-dimensional object. It is measured in square units (e.g., cm², m², in²) and represents how much material would be needed to completely cover the shape.
The surface area of a cube is calculated using the formula SA = 6a², where ‘a’ is the length of one side. Since all six faces of a cube are identical squares, you simply square one side length and multiply by six.
Total surface area includes every face of the 3D shape, including the top and bottom bases. Lateral surface area only includes the side faces, excluding the base(s). For example, a cylinder’s lateral surface area is 2πrh, while its total surface area is 2πrh + 2πr².
The surface area of a sphere is calculated using the formula SA = 4πr², where ‘r’ is the radius. This formula was first proven by Archimedes, who showed that the surface area of a sphere is exactly four times the area of its greatest circle.
Surface area calculations are essential in construction (painting walls, tiling floors), manufacturing (packaging design, material costs), engineering (heat dissipation, coating requirements), and science (chemical reaction rates, biological cell efficiency).